One particularly striking example: I had CC do some work and then kicked off a "/codex-review" and while it was running went to test the changes. I found a deadlock but when I switched back to CC the Codex review had found the deadlock and Claude Code was already working on a fix.
https://github.com/openai/codex-plugin-cc
I actually work the other way around. I have codex write "packets" to give to claude to write. I have Claude write the code. Then have Codex review it and find all the problems (there's usually lots of them).
Only because this month I have the $100 Claude Code and the $20 Codex. I did not renew Anthropic though.