If you mean Codex is better at planning, I've heard the exact opposite. I'm told it's a beast if you tell it exactly what you need as it will execute it to the T whereas Claude will push back or do its own thing either because it thinks it's wrong or because it's feeling lazy
gpt-5.4 xhigh is a beast you only wanna unleash on your most complex tasks or spend 30 minutes watching the model reasoning how to do a git commit. For everything else i'd happily use a saner model like sonnet.
I've started hitting Codex quota regularly for the first time the last couple of weeks, so I feel like they might be tightening the screws on the $20/month plan too. Someone paying for Max might have to work at it to hit the quota