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.