I am glad I am not the only one experiencing this. It seems like it's as good or better at actually writing code compared to 4.8 but it is a lot worse to work with.

Its even more sycophant-y than it was before, if you ask it a question it almost always says "You're right, let me change this..." even though there wasn't even something always wrong with it.

It also seems to pour a ton of resources into developing features I didn't ask for or investigating bugs that aren't related to what I am doing.

Before if you wrote specific enough instructions it would usually just do what you said and flag any concerns, now it just goes ahead in whatever direction it feels.

It also keeps inventing terminology that doesn't exist in writing 10 paragraphs to say one thing.

I really hope it's not trying to drive up token use.