After several more days of intense usage of GPT-5 via Cursor and via the GPT-5 Pro model in the web app, I stand by everything I said about it being a much smarter model and better at coding than Opus 4.1 I still like Opus and do find the ergonomics of Claude Code to be nicer in many ways, but if you’re trying to do truly difficult stuff that requires really clever first-principles thinking and computer science chops, GPT-5 is next level. But I suspect this only emerges when the reasoning effort mode is set to at least medium, and really manifests itself with the high effort setting. A good example problem is preparing document “redlines” of two long, complex legal documents. Not different versions of the same document, but two different documents that come from a shared general template. This is a very, very hard problem to do a good job on, and requires many clever tricks and heuristics to give decent performance and output quality (I’m talking about using traditional programming techniques here, not using LLMs to do this comparison). GPT-5 with Cursor agent can simply come up with more, better, clever (yet pragmatic) ideas faster, and implement these correctly and without much hand-holding, compared to Opus4.1. It depends on what you’re working on, though. I still think I prefer frontend code in NextJS by Opus, for example. But you should absolutely check for yourself on your own actual problems and not trust all the many people saying the model sucks and that it’s proof we’ve hit a wall. Either they’re using the bad free version without thinking, or they have no clue how to prompt effectively, or they’re letting their feelings towards OpenAI and Altman color their views.