The GPT models, in my experience, have been much better for backend than the Claude models. They're much slower, but produce logic that is more clear, and code that is more maintainable. A pattern I use is, setup a Github issue with Claude plan mode, then have Codex execute it. Then come back to Claude to run custom code review plugins. Then, of course review it with my own eyes before merging the PR.

My only gripe is I wish they'd publish Codex CLI updates to homebrew the same time as npm :)

GPT-5 was the first model that occasionally produced code that I could push without any changes

Claude still tends to add "fluff" around the solution and over-engineer, not that the code doesn't work, it's just that it's ugly

Interesting, I have consistently found that Codex does much better code reviews than Claude. Claude will occasionally find real issues, but will frequently bike shed things I don't care about. Codex always finds things that I do actually care about and that clearly need fixing.

I’d agree with you until Opus 4.5.

Eh sonnet 4.5 was better at Rust for me