I think the biggest tell for me was having the leader of Cursor up vouching for the model, who has been a big proponent of Claude in Cursor for the last year. Doesn't seem like a light statement.
I would agree. I am a big fan of Claude and I've Claude code a bunch although after testing Codex & GPT-5 extensively, it just gets stuck in a rut way less often and much more often is able to pinpoint issues & fixes in the codebase.