I’m basically only using the Codex CLI now. I switched around the GPT-5 timeframe because it was reliably solving some gnarly OpenTelemetry problems that Claude Code kept getting stuck on.

They feel like different coworker archetypes. Codex often does better end-to-end (plan + code in one pass). Claude Code can be less consistent on the planning step, but once you give it a solid plan it’s stellar at implementation.

I probably do better with Codex mostly due to familiarity; I’ve learned how it “thinks” and how to prompt it effectively. Opus 4.5 felt awkward for me for the same reason: I’m used to the GPT-5.x / Codex interaction style. Co-workers are the inverse, they adore Opus 4.5 and feel Codex is weird.