There's an often hard to express subjective experience you get with a new model, especially if you spend a lot of time trying out different ones.

I believe the people who feel like Fable is a big improvement, for me it's just much more reasonable and grounded.

It makes me realize how much of a try hard over optimizing planner GPT 5.5 can be. I've been fighting it often to simplify plans.

But no matter the model you can't trust them to actually deliver on very long tasks while maintaining quality. At least not without external orchestration and review.