have to agree on that, there's the variation, it's faster if you take it's code verbatim, run it, and debug where there's obvious problems... but then you are vulnerable to unobvious problems, when a hacky way of doing it is weak to certain edge cases... and no real way to do it.

Reading it's code, understanding it, finding the problems from the core, sounds as time consuming as writing the code.

On the code competition, I think it can do like 2 or 3 lines in particular scenarios. You have to have an instinct for "are the next three lines so blatantly obvious it is actually worth reading the suggestion, or just ignore it because I know it's going to screw up without even looking".

Very very very rarely do I find prompt driven coding to be useful, like very boilerplate but also very tedious. Like "show user to specify these three parametets in this cli utility", and poof, you got a reasonable argv handling pretty reliably.

Rule of thumb is if a viable answer could be expected during an interview by a random junior code applicant, it's worth giving the llm a shot. If it's something that a junior developer could get right after learning on the job a bit, then forget it, the LLM will be useless.