I have had GPT-5 point out dozens of complex bugs to me. Often in these cases I will try to see if other models can spot the same problems, and Gemini has occasionally but the Claude models never have (using Opus 4, 4.1, and Sonnet 4.5). Not once, which continues to surprise me. They can still be good at pointing out trivial bugs like typos, mismatching error messages, or really obvious bugs though.
If you haven’t tried it, I would try the codex /review feature and compare its results to asking Sonnet to do a review. For me, the difference is very clear for code review. For actual coding tasks, both models are much more varied, but for code review I’ve never had an instance where Claude pointed out a bug that GPT-5 missed. And I use these tools for code review all the time.
How many of those were real and how many hallucinated?
I've been a Claude Code fanboy for many months but OpenAI simply won this leg of the race, for now.
Codex meanwhile seems to be smarter and plugs away at a massive todo list for like 2 hours
It’s always interesting to see others opinions as it’s still so variable and “vibe” based. Personally, for my use, the idea that any GPT-5 model is superior to Claude just doesn’t resonate - and I use both regularly for similar tasks.