Always hard to say for sure because I'm not sitting around running the exact same situations through both models in parallel to compare them.
It feels like you can give it a big chunky problem and leave it alone and it gets it done, with less questions and fewer design decisions that I wouldn't have made.
In reviewing its code I'm finding less to complain about than Opus. But it's all vibes, if you want a more scientific comparison you'll have to look elsewhere.
He has early access to anthropic models, of course he will hype them up, so that they will keep sharing access to preview models with him (and more traffic to his website). It also does't require him to perform any rigorous analysis of model performance, just share how it feels:
> But it's all vibes, if you want a more scientific comparison you'll have to look elsewhere.
I gave it a complete database migration of our app, opus failed hard each time... Untyped Json b for some rows, no proper normalisation, falling back asking me questions in between.
Fable just did it, clean code, one timeout with a hanging bash script, fixed a couple very old very structural bugs in the codebase
Always hard to say for sure because I'm not sitting around running the exact same situations through both models in parallel to compare them.
It feels like you can give it a big chunky problem and leave it alone and it gets it done, with less questions and fewer design decisions that I wouldn't have made.
In reviewing its code I'm finding less to complain about than Opus. But it's all vibes, if you want a more scientific comparison you'll have to look elsewhere.
I did a qualitative side-by-side of Claude Fable vs Opus 4.8 vs ChatGPT 5.5
https://generative-ai.review/2026/06/claude-fable-rush-test-...
I get them to make a 3D explainer animation. You can clearly see Fable is much improved on both Opus 4.8 and ChatGPT 5.5.
Better Textures . A nifty camera follow . Humans rendered better . ... see for yourselves
Honestly, they all look good
But you said you've been working on those problems for months, so didn't you throw those same problems at Opus?
He has early access to anthropic models, of course he will hype them up, so that they will keep sharing access to preview models with him (and more traffic to his website). It also does't require him to perform any rigorous analysis of model performance, just share how it feels:
> But it's all vibes, if you want a more scientific comparison you'll have to look elsewhere.
Crank up more revenue for IPO
I gave it a complete database migration of our app, opus failed hard each time... Untyped Json b for some rows, no proper normalisation, falling back asking me questions in between.
Fable just did it, clean code, one timeout with a hanging bash script, fixed a couple very old very structural bugs in the codebase
How did you do this impressive amount of work and verify that it did it perfectly all in one day?
I told Claude to do it yesterday evening, checked in during my nightly break.
I am not sure it's perfect, and it will need further validation
This morning I looked at code samples & checked if all unit/integration and e2e pass & perfomance tests pass
I also generated a postgres schema diagram.
Aka I did probably 2 hours of work, rest was not me
The opus try was last month