I asked both to help me with a hardware bug. Codex kept trying things, being sure of what the problem is every time, and every time making it worse.
Opus went off and browsed my dependencies for ten minutes, and came back and solved the problem firs try.
Heh, I find Codex to be a far, far smarter model than Claude Code.
And there's a good reason the most "famous" vibe coders, including the OpenClaw creator all moved to Codex, it's just better.
Claude writes a lot more code to do anything, tons of redundent code, repeated code etc. Codex is only model I've seen which occasionally removes more code than it writes.
Funnily enough I've been using Codex 5.3 on maximum thinking for bug hunting and code reviews and it's been really good at it (it's just seem to have a completely different focus than Opus.)
I generally don't like the way codex approaches coding itself so I just feed its review comments back in to Claude Code and off we go.