neah, I believe most people here, which immediately brag about codex, are openai employees doing part of their job. otherwise I couldn't possibly phantom why would anyone use codex. In my company 80% is claude and 15% gemini. you can barely see openai on the graph. and we have >5k programmers using ai every day.
Currently GPT just works much better, and so does Gemini but it's more expensive right now. Going through Opencode stats, their claim is that Gemini is the current best model followed by GPT 5.4 on their benchmarks, but the difference is slim.
My personal experience is best with GPT but it could be the specific kind of work I use it for which is heavy on maths and cpp (and some LISP).