I can't speak to other uses such as coding, but as a sounding board GPT-5 is better than GPT-4o, which was already pretty good. GPT-5's personality has definitely shifted to a more professional tone which I like.

I do understand why people are missing the more synchophant persoanlity of GPT-4o, but I'm not one of them.

I don’t feel like I got anything new, I feel like something got taken away.

Upon some digging, it seems that part of the slowdown is due to the gpt-5 models by default doing some reasoning (reasoning effort "medium"), even for the nano or mini model. Setting the reasoning effort to "minimal" improves the speed a lot.

However, to be able to set the reasoning effort you have to switch to the new Response API, which wasn't a lot of work, but more than just changing a URL.

Code seems to work on the first try more often for me too.

Perhaps my favorite change so far is the difference of verbosity. Some of the responses I am receiving when asking trivial questions are now are merely a handful of sentences instead of a dissertation. However, dissertation mode comes back when appropriate, which is also nice.

Edit: Slightly tangential, but I forgot to ask, do any of you all have access to the $200/month plan? If so, how does that model compare to GPT-5?

I’m reminded of that Louis CK joke about people being upset about the WiFi not working on their airplane.