For me it seemed to slow down the responses, could have been anything that though. I only used it to grammar check some of my articles, so nothing major. I didn't notice any difference in what I was using it for, so cancelled it after the first month.
claude.ai is good at programming, but gpt4.0o is really poor at programming. I still think 3.5 is the best for programming with chat gpt, if that is what you need it for.
It does slow down the responses, as they rate limit it even if you're on Plus. However, now they have limited non-plus users to 1 interactive message (ie. a google search, or something that uses "Tools") every X hours, Plus really is worth it. I've coded all sorts with Plus, and I use ChatGPT every single day simply as a better search engine.