@d-healey That wasn't my experience at all. Search the internet for "GPT5 fails" and you'll see all the negative reactions.
In my case it was very slow, showed way too much 'thinking' text, refused to execute terminal commands and had a much higher hallucination rate than previous GPT versions or Claude.
Keep in mind, this wasn't with HISE. This was mainly in a Ruby on Rails app with ~30k LOC and a bunch of other much smaller projects. I haven't used AI for HISE at all yet, mainly because I don't think there's enough HISE code out there for it to give really useful answers.
For casual stuff it might be fine, but for coding - and in particular in the Cursor IDE, it was horrible.