Mixed
GPT codex just messes up a lot for me. Whatever I'm doing with it, it's not working
muzani on Hacker News
In the thread “Ask HN: Claude Opus 4.5 vs. GPT 5.1 Codex Max for coding. Worth the upgrade?”
Helped: Opus 4.5 evaluating code intent in undocumented codebases.
Got in the way: GPT Codex consistently messing up tasks for the user.
… It's perfect for PRs - caught things like people submitting code that looks right, but ended up running a poorly documented/incomplete method. GPT codex just messes up a lot for me. Whatever I'm doing with it, it's not working. The plain GPT-5.2 is good overall, but it confidently makes mistakes and tell you that it's done. …