I've been using Claude code most of the year, and codex since soon after it released:
It's important to separate vibes coding from vibes engineering here. For production coding, I create fairly strict plans -- not details, but sequences, step requirements, and documented updating of the plan as it goes. I can run the same plan in both, and it's clear that codex is poor at instruction following because I see it go off plan most of the time. At the same time it can go on its own pretty far in an undirected way.
The result is when I'm doing serious planned work aimed for production PRs, I have to use Claude. When it's experimental and I don't care about quality but speed and distance, such as for prototyping or debugging, codex is great.
Edit: I don't think codex being poor at instruction following is inherent, just where they are today
It's important to separate vibes coding from vibes engineering here. For production coding, I create fairly strict plans -- not details, but sequences, step requirements, and documented updating of the plan as it goes. I can run the same plan in both, and it's clear that codex is poor at instruction following because I see it go off plan most of the time. At the same time it can go on its own pretty far in an undirected way.
The result is when I'm doing serious planned work aimed for production PRs, I have to use Claude. When it's experimental and I don't care about quality but speed and distance, such as for prototyping or debugging, codex is great.
Edit: I don't think codex being poor at instruction following is inherent, just where they are today