Reg PRs - for the ones with complex requirements what I am seeing is that time to initial PR is very short, and a ping-pong between the reviewer and developer begins, because in my cases (not all) the developer vibe-coded parts, and they didn't really understand the requirements deeply or their code, and it takes multiple iterations for them to fix it. You can argue this is a human problem but this is the net effect I'm seeing.

I am not sure but for complex cases it seems to me that the earlier sum of moderately long PR time + moderately long review time has been replaced by very short PR time + even longer review time. I am not sure if there's a net gain in these cases. Sometimes even if the code is functionally correct, it's verbose enough (e.g., too many intermediate functions) that I think they will impact future reviews.