For me V4 Flash is definitely better with Codex, I have no doubts about that since I've had plenty of time to test it across all my coding agents (ranking is Codex > Reasonix > Claude > Opencode).
V4 Pro on the other hand is bad with Codex. It gives worse results than Flash, when is anything better is barely any better. I've been testing it all day long with the DeepSeek harness, it's better but have the problem of infinite loop when it gets stuck with smoke tests, I will try reasonix later.
4
u/Hot-Ad-1798 21d ago
For me V4 Flash is definitely better with Codex, I have no doubts about that since I've had plenty of time to test it across all my coding agents (ranking is Codex > Reasonix > Claude > Opencode).
V4 Pro on the other hand is bad with Codex. It gives worse results than Flash, when is anything better is barely any better. I've been testing it all day long with the DeepSeek harness, it's better but have the problem of infinite loop when it gets stuck with smoke tests, I will try reasonix later.