GPT 6.1 Sol is our new champ

Another week, another new model. This time it is GPT Sol 6.1 arriving, so I’ve put it to the test against the current champion GPT Astra 6 and found:

GPT Sol 6.1 beats Astra 6 – https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260930-Cowork-GPT61Sol-Grok-eval.md

but it is more expensive than Astra 6:

Opus 5.5 = 23,494 credits

GPTSol 6.1 = 10,173 Credits

GPT Astra 6 = 6,067 credits

Fable 5.1 = 3,453 credits

Fable 5 (Preview) = 3,387 credits [Model no longer shown]
Fable 5 (Copilot)(Preview) = 3,373.8 credits [Model no longer shown]

GPT 5.6 Sol = 2,800.50 credits [Model no longer shown]
Sonnet 5 = 2,509.3 credits [Model no longer shown]
Opus 4.8 = 2,487 credits [Model no longer shown]

GPT Sol 6 = 2,243 credits [Model no longer shown]

Opus 5 = 2,240 credits [Model no longer shown]

GPT 5.5 = 1,200 credits
GPT 5.6 Terra = 260 credits [Model no longer shown]

Interestingly, Sol 6.1 generated a 73 page report while Astra 6 was only 35! That’s 2 x the output. Stop and think about that, 73 detailed pages with a single prompt! Amazing!

I also compared it to its predecessor, GPT Sol 6 and found – https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260930-Cowork-GPT6-61Sol-Grok-eval.md

GPT 6.1 Sol is also the clear winner here as the results show. Again, an amazing improvement jump by my comparison from only Sol 6.0 to Sol 6.1! Where is this going to end?

The summary of the all the outputs produced is here:

https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260816-File-paramters.md

while the results, including outputs are here:

https://github.com/directorcia/general/tree/master/Copilot/Comparisons

How much better can these models get? We’ll know shortly, I’ll bet.

Astra still wins but not on cost

With GPT 6 Sol now also available in Copilot, it is time for the LLM battle to continue and the results are in.

Astra 6 beats Sol 6 – https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260923-Cowork-GPT6Sol-Grok-eval.md

However, GPT 6 Sol is very cheap at 2,243 credits and that ranks towards the bottom of costs in Cowork as seen here.

Opus 5.5 = 23,494 credits

Astra 6 = 6,067 credits

Fable 5.1 = 3,453 credits

Fable 5 (Preview) = 3,387 credits [Model no longer shown]
Fable 5 (Copilot)(Preview) = 3,373.8 credits [Model no longer shown]

GPT 5.6 Sol = 2,800.50 credits
Sonnet 5 = 2,509.3 credits
Opus 4.8 = 2,487 credits [Model no longer shown]

GPT 6 Sol = 2,243 credits

Opus 5 = 2,240 credits

GPT 5.5 = 1,200 credits
GPT 5.6 Terra = 260 credits

I also decided to pit the recent Claude models against each other and found:

Opus 5.5 beats Fable 5 – https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260923-Cowork-F51vO55-Grok-eval.md

and it did so quite significantly if you look at the report. Opus 5.5 is clearly superior to Fable 5 according to my rudimentary benchmark. So it is really good but also really (really) expensive.

Remember, all the reports and created documents are here so you can judge for yourself:

https://github.com/directorcia/general/tree/master/Copilot/Comparisons

Let me know what you find.

Astra takes the trophy

In the last round of the Copilot LLM challenge Fable 5.1 came out on top. You can find that here:

https://blog.ciaops.com/2026/09/02/we-have-a-new-llm-in-copilot-winner/

That was then and this is now. Less than a month later a new model from OpenAI, GPT 6 Astra has become available in Copilot (Cowork specifically). I therefore pitted Astra 6 against the reigning champion Fable 5.1. The result is, unsurprisingly, that we have a new winner:

GPT 6 Astra

and you can see the results for yourself here:

https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260917-Cowork-Grok-eval.md

with all the outputs here:

https://github.com/directorcia/general/tree/master/Copilot/Comparisons/20260816

Interestingly, there was only a small improvement last time when Fable 5.1 pipped Opus 5 by 8.7 to 8.5 in the overall score. This time however Astra won by a significant margin of 9.03 to 8.30.

Again, not unsurprisingly, where Astra lost out was on cost, almost doubling the cost of Fable 5.1 as you can see:

Astra 6 = 6,067 credits

Fable 5.1 = 3,453 credits

Fable 5 (Preview) = 3,387 credits [Model no longer shown]
Fable 5 (Copilot)(Preview) = 3,373.8 credits [Model no longer shown]

GPT 5.6 Sol = 2,800.50 credits
Sonnet 5 = 2,509.3 credits
Opus 4.8 = 2,487 credits [Model no longer shown]
Opus 5 = 2,240 credits

GPT 5.5 = 1,200 credits
GPT 5.6 Terra = 260 credits

So the latest model is the best (unsurprising). The latest model is also the most expensive (unsurprising).

I have also updated the summary report for all the documents created by the different models here:

https://github.com/directorcia/general/blob/master/Copilot/Comparisons/20260816-File-paramters.md

I’m sure there will be more model releases coming soon but my rudimentary testing certainly indicates they are improving, if somewhat more expensive each time.