Just a minute ago 5.5 looked at some human-written code of mine from last year and while it was making the changes I asked for it determined the existing code was too brittle (it was) and rewrote it better. It didn't mention this in its summary at the end, I only know because I often watch the thinking output as it goes past before it hides it all behind a pop-open.
I also find I need to run an llm code review or two against any code it produces to even get to the point where’s it’s ready for human review.
In any case they served as an extremely valuable tool.