AIThis post was created with the assistance of artificial intelligence (AI).

🔍 Read the full analysis: How My September 2026 AI Tools Handle Different Jobs on ThorstenMeyerAI.com

Buying for a business?Offer from Amazon

Get business pricing on monitors, keyboards and dev gear

  • Business-only prices and quantity discounts
  • Tax-exempt purchasing
  • Multiple users, one account, clear invoices
As an affiliate, we earn on qualifying purchases.

TL;DR

A Sept. 29, 2026, comparison of six AI models argues that task cost and effort settings matter as much as benchmark scores. Its author uses Claude Opus 5.5 for building and GPT-6.1 Sol for detailed review, while reserving other models for narrower jobs. The figures come from Artificial Analysis Intelligence Index v4.3.x and are not proof of performance on every workload.

Thorsten Meyer’s Sept. 29, 2026, model comparison assigns Claude Opus 5.5 to building software and GPT-6.1 Sol to detailed review, arguing that estimated task costs can differ sharply even among models with relatively close benchmark scores. The report matters to teams choosing AI tools because it frames model selection as a trade-off among quality, effort settings and cost, while its results remain benchmark-based rather than verified for each reader’s work.

The comparison covers six models using Artificial Analysis Intelligence Index v4.3.x scores and the source’s cost-per-task estimates. Opus 5.5 leads at 58 index points in its top setting, with an estimated cost of $5.98 per task. GPT-6.1 Sol reaches 51 at xhigh for $0.39; GPT-6 Luna scores 37 at $0.07. The report lists Sonnet 5.5 at 56 and $7.60, Fable 5.1 at 53 and $7.63, and GPT-6 Astra at 53 and $3.26.

Meyer recommends Opus 5.5 at high for routine development, citing a score of 54 and estimated cost of $1.82 per task. He reserves xhigh, at 56 and $3.46, for work such as architecture and migrations. He places GPT-6.1 Sol at high or xhigh for examining specific files and reviewing changes, and says a different model family can provide a useful second review. These are the author’s workflow choices, not independent evaluations of software quality.

The report says effort settings can change estimated costs substantially. For Opus 5.5, moving from medium to max raises the score from 51 to 58 while increasing estimated task cost from $1.34 to $5.98. For Sonnet 5.5, the listed max setting costs $7.60 for a score of 56, compared with $2.74 and a score of 52 at xhigh. Meyer says this makes Sonnet’s high setting a better fit for scoped tasks and documents.

At a glance
reportWhen: Published Sept. 29, 2026; GPT-6.1 Sol w…
The developmentThorsten Meyer published a Sept. 29 comparison assigning six AI models different jobs based on benchmark scores, effort settings and estimated cost per task.

Opus builds. Sol reviews. Jev decides.

The September 2026 AI stack in one page: six frontier models on one price curve, and a decision model for the high-volume judgements that do not need a sentence.
Scores: Artificial Analysis Intelligence Index v4.3.x. Data as of 29 September 2026.
BuildsClaude Opus 5.5 at high or xhigh effort
Digs and reviewsGPT-6.1 Sol at high or xhigh effort
DecidesJev on high-volume yes/no and routing calls

One price tape, six models

Put every model on the same cost-per-task ruler and capability looks compressed. The bill does not.
Price tape: cost per task of six models on a log scale, from GPT-6 Luna at $0.07 to Fable 5.1 at $7.63$0.05$0.10$0.50$1$5$10cost per task, log scale: each tick is a different order of magnitudeGPT-6 Lunaindex 37 · $0.07GPT-6.1 Solindex 51 · $0.39 (xhigh)GPT-6 Astraindex 53 · $3.26Opus 5.5index 58 · $5.98Sonnet 5.5 · index 56 · $7.60Fable 5.1 · index 53 · $7.63about 100× from the cheapest to the priciest, but only 21 index points between them

Score against cost, at every effort setting

Each dot is an effort level. Opus 5.5 at high already matches Astra and Fable at max on this index, for less money.
Intelligence Index score against cost per task for each effort setting of six models$0.01$0.10$1$102030405060cost per Intelligence Index task, log scaleindexOpus high / xhigh: my defaultOpus 5.5Sonnet 5.5Fable 5.1GPT-6 AstraGPT-6.1 Sol (new)GPT-6 Sol (Sep 22), dashedGPT-6 Lunaup and to the left is better
Astra and Fable are shown at their top published setting. Luna starts at $0.0045 per task. GPT-6.1 Sol has no low or max setting published yet.

The effort dial moves the bill more than the model

Going from medium to max on Opus costs 4.46× more for 7 points. That is why I run high or xhigh.

Claude Opus 5.5

$0.55
42
$1.34
51
$1.82
54
$3.46
56
$5.98
58
low
medium
high
xhigh
max
Solid bars are where I run it. Max adds 2 points over xhigh for 73% more cost.

Claude Sonnet 5.5

$0.41
36
$0.59
41
$1.08
47
$2.74
52
$7.60
56
low
medium
high
xhigh
max
Best value is high. At max it writes about 193k output tokens per task, the most measured.

GPT-6.1 Sol: near-Astra scores at a fraction of the price

Launched 29 September at $2 in and $10 out per 1M tokens. It sits 1 to 2 points under Astra and Fable, and Opus xhigh still leads it by 5.

Three published settings

SettingIndexCost per taskOutput tokensFirst token
medium48$0.2115M5.3 s
high50$0.3225M57 s
xhigh51$0.3936M69 s
Median for comparable models is 82M output tokens. High and xhigh are not interactive: plan for a wait before the first token.

Same score band, very different bill

GPT-6.1 Sol xhigh
$0.39index 51
Opus 5.5 high
$1.82index 54
GPT-6 Astra max
$3.26index 53
Opus 5.5 xhigh
$3.46index 56
Fable 5.1 max
$7.63index 53
Cost per Intelligence Index task. A one-point gap is inside the noise.

My stack: who builds, who reviews

Opus does the work. A second model family reviews it, because a different reviewer catches what the author cannot see.
Stack diagram: Opus 5.5 builds at high effort, escalates to xhigh, and sends every change to GPT-6.1 Sol for review; Astra or Fable give a second opinionOpus 5.5 · xhighhard problems: architecture,migrations, trust boundariesOpus 5.5 · highMAIN BUILDERfeatures, APIs, multi-filework, refactorsescalate when it gets hardGPT-6.1 Solhigh or xhighdigs into details andreviews every change$0.32–0.39 per taskdifffindingsAstra or Fablesecond opinion, 8 to 20×the cost per taskif they disagreeSonnet 5.5 · Lunaside work: scopedsubtasks, bulk checksand routingFailed review? Hand Opus the failing case and the evidence.Never just “try harder”: effort cannot supply a missing requirement.
Effort is not capability. Turning the dial up does not make a model smarter.
Effort cannot fill gaps. A missing requirement stays missing at any setting.
Different model, same spec. That is not independent review if both read the same flawed brief.
Green tests are not approval. Passing tests only prove what the tests cover.

Cheaper tokens are not cheaper work

Illustrative, not measured: $1 of model time plus 4 minutes of review at $45 an hour. Halving the model price saves 12.5% of the total. One extra minute of review erases it.
$4.00
review $3.00
model $1.00
Baseline
$3.50
review $3.00
model $0.50
Model price cut 50%
$4.25
review $3.75
model $0.50
Cheaper model plus 1 extra minute of review
Track cost per accepted result: model, tools, review and rework, divided by the results someone actually uses.

Read the numbers with four warnings

The index movesFable scored 66 on an earlier version and 53 on v4.3. Compare within one version only.
Fallback is includedFlagged cyber and biology tasks route to older Anthropic models, now on Sonnet 5.5 too.
Max is not productionReal deployments run medium or high, where gaps narrow and costs fall.
Your work decidesShadow-test on your own tasks. Budget cost per task, not per token.

Part 2: Jev, the model that decides instead of writing

Jev cannot write, summarise or extract. It answers narrow typed questions with a probability and an honest confidence, in under a second, for about $0.04 per million input tokens.

One call in, typed answers out

Your code, not Jev, decides what to do with each answer, usually by confidence band.
Jev flow: state and typed questions go into one Jev call; typed answers with confidence come out; code acts alone, escalates the gray zone, or logsStatea ticket, a story,a site profile,a log line …+ typed questions,many per callJevone call0.3 to 0.9 s$0.042 / M tokens inAnswersnoul: 0.03choice: billing p 0.91, conf 0.86score: 2.7 of 3 conf 0.64code branches on thisAct aloneconf ≥ 0.8Escalategray zone toLLM or humanLogmeasure first

Three question types

noul
A yes/no question. Returns the probability of yes, 0 to 1.
gates, flags, filters
choice
Pick one option. Returns the choice, a probability per option, and a confidence.
routing, classification, taxonomy
score
Rate on your ordered levels. Returns a position (it can fall between levels) plus a confidence.
quality, fit, severity, priority

Confidence is the superpower

In my own measurement on a 31-topic classification, Jev agreed with a frontier LLM almost every time it was sure, and rarely when it was not. So: decide the clear cases, route the gray zone.
confidence 0.8 or higher
97–99%
all answers
89%
confidence below 0.5
42%
Agreement with a frontier LLM, my production data, September 2026, rounded.

Three uses running in my publishing operation

About 90,000 decisions so far. Checks I could only afford on a sample now cover everything.
$2.01
Language check
78,889 articles scanned overnight. 1,576 in the wrong language found, 1,553 fixed in place.
22%
Relevance gate
About 10,000 story-to-site pairings judged in 3 days. Only 22% were clearly on-topic.
89%
Classifier fallback
Agreement with the primary LLM across 31 topics, used when that LLM errors.

The fit test, then the shadow test

Use Jev only when all four hold. Then prove it on past decisions before it acts on anything.
High volumeThousands of small calls, not a handful of big ones.
Narrow questionNo multi-step reasoning needed.
Cheap errorsOr unsure cases go to something smarter.
Heuristic failsVisibly, and measured, not assumed.
  1. Replay 300 to 500 past decisions
  2. Compare overall and per confidence band
  3. Read 20 disagreements, decide who was right
  4. High band at 95% or better?
  5. Own flag, off by default
  6. Canary on 5 to 10 units
  7. Roll out in the confident band only

24 use cases, sorted by how well they fit

Start from the strong fits. The amber ones need a measurement before you trust them, and the red ones fail one of the four conditions.
in productionstrong fitmeasure firstpoor fit

Proven in production

  • 1Relevance gate
  • 2Language check
  • 3Classifier fallback

Publishing and content

  • 4Thin-source detector
  • 5Same-event dedupe
  • 6Product fits roundup
  • 7Disclosure present
  • 8Headline quality
  • 9Comment moderation

Commerce and support

  • 10Support-ticket routing
  • 11Return-reason coding
  • 12Review to feature complaints
  • 13Catalogue taxonomy
  • 14Order-fraud pre-triage

Software and AI systems

  • 15LLM guardrail
  • 16RAG passage filter
  • 17Citation check
  • 18Tool and intent routing
  • 19Log-line triage
  • 20PR risk triage

Business ops and home

  • 21Inbox triage
  • 22Expense categorisation
  • 23Lead qualification
  • 24Smart-home intent

Limits, cost and one hard rule

No writing, summarising or extractionPair it with an LLM for the write step.
No world knowledgePut a snippet in the state; a bare name means nothing.
Reads your wording literallyA rewording moved my results about 2 points. Freeze it, re-measure after changes.
Weaker on non-English, maths, datesKeep those checks on an LLM. Early access, hosted API only.
100,000 decisions ≈ $2.50
About 60M input tokens at $0.042 per million, output free, roughly 600 tokens per three-question call. Latency 0.3 to 0.9 seconds.
Never the sole decision-maker for consequences about people. Hiring, credit, medical and legal outcomes stay with a human. Jev can sort and flag. A person decides.
Sources. Model scores, cost per task and speeds: Artificial Analysis, Intelligence Index v4.3.x, including the GPT-6.1 Sol medium, high and xhigh pages, checked 29 September 2026. Astra and Fable scores from the Artificial Analysis v4.3 announcement. Jev figures are my own production measurements, September 2026, rounded. The review-bill example is illustrative. Read the full article on thorstenmeyerai.com.

Cost Shapes the Model Assignment

The report’s central implication is that the highest score may not be the most economical choice for every task. Meyer’s figures put GPT-6.1 Sol’s xhigh estimate at $0.39 per task, compared with $3.26 for Astra and $7.63 for Fable 5.1, while their top scores sit within a few points of one another. If those estimates translate to a team’s own workload, using a lower-cost model for repeated reviews or classification could affect operating costs.

But the comparison itself does not establish that the models produce equivalent results on a particular company’s code, documents or routing decisions. Meyer advises readers to shadow-test models against their own quality bar before switching. He also cautions that savings in model charges may be outweighed by added human review time; his example is illustrative, not a measured result.

A New Model Joins the Comparison

The source dates the releases across September: Fable 5.1 on Sept. 1, Astra on Sept. 3, Opus 5.5 on Sept. 22, Luna on Sept. 22 and Sonnet 5.5 on Sept. 28. GPT-6.1 Sol was released Sept. 29, the day the comparison was published. The author says it has the same listed token prices as GPT-6 Sol: $2 per million input tokens and $10 per million output tokens.

The Artificial Analysis Intelligence Index is described in the source as a measure of general capability, rather than a verdict on a specific workload. The report also lists token output and time-to-first-token figures for Sol: at high, 25 million output tokens on the index and 57 seconds to first token; at xhigh, 36 million and 69 seconds. The author says these longer waits make those settings unsuitable for interactive use.

“The practical reading: Sol is not the model I ask to build. It is the model I can afford to run on everything.”

— Thorsten Meyer

Workload Results Remain Open

The source does not provide independent, task-specific comparisons showing how the models perform on readers’ workloads. Its per-task costs are estimates tied to the stated index runs, and the material supplied does not fully define the task-cost calculation or its applicability to other usage patterns. Meyer also says one index point is within the noise, and Artificial Analysis had not published low or max settings for GPT-6.1 Sol at the time of writing. The report does not establish whether the listed costs or benchmark standings will hold as models and pricing change.

Test Before Changing Workflows

Meyer’s proposed next step is for teams to shadow-test candidate models on their own tasks before changing assignments. That would let them compare output quality and review time against actual costs. The source gives no date for new benchmark settings or a follow-up comparison, so the timing of further updates is unclear.

Key Questions

Which model does Meyer use for building?

He says he uses Claude Opus 5.5 at high for routine development, and xhigh for harder work such as architecture and migrations.

Why does he use GPT-6.1 Sol for review?

Meyer cites its estimated cost of $0.32 at high and $0.39 at xhigh and uses it to inspect files and diffs. He says a different model family can act as a second reviewer; this is his practice, not a guarantee of independent or correct review.

Does the benchmark show which model is best for every task?

No. The source describes the Artificial Analysis Intelligence Index as a general capability measure and recommends testing models on the work they would actually handle.

What remains unknown about the cost figures?

The supplied report does not fully explain how its per-task estimates translate to other workloads or usage patterns. Teams would need to compare their own quality, usage and human review costs.

Source: ThorstenMeyerAI.com

FALL

Fall Picks

As an affiliate, we earn on qualifying purchases.

You May Also Like

Pixel Watch 5

Details of the upcoming Pixel Watch 5 have leaked, revealing design updates, new features, and release timing, with official confirmation pending.

Unveiling Seedream 5.0 Pro: ByteDance’s Latest AI Model For Precision, Control, And Multilingual Imaging

ByteDance unveils Seedream 5.0 Pro, a multimodal AI with advanced layer editing, multilingual precision, and production controls, targeting professional creators.

9 Best WiFi 7 Routers In 2026

Discover the 9 best WiFi 7 routers in 2026, featuring speed, coverage, and ease of setup to enhance your home network performance.

Build vs Buy a Prebuilt AI Workstation

Struggling to choose between building or buying an AI workstation? Discover the cost, performance, and control tradeoffs to make the smart move in 2026.