I recently switched from Opus/Fable to GPT 5.6 Sol, and so far I’ve found it so dumb that it often makes me lose time. I can ask Opus/Fable one thing and I know it’ll take some time but will do it almost perfectly. With GPT I constantly have to steer it; its investigations almost always end up with overreached conclusions after minutes of looking in random places unrelated to the issue; it adds a lot of useless defensive code just like previous 5.x models. I do use AGENTS.md; I have a couple of MCPs; I enabled memories.

I see people happy about GPT 5.6 Sol everywhere, so there must be something I’m missing. If you’ve tested both model families, what have been your experience so far? Have you noticed that some things that work well with Claude don’t with GPT or vice-versa?