Never used it. Don't see any reason to. I just type stuff in my IDE. Works like a charm.

Most of the time I'm not writing large volumes or boilerplate code or anything, I'm making precise changes to solve specific problems. I doubt there's any LLM that can do that more effectively than a programmer with real knowledge of the code base and application domain.

I also work on open source software and we haven't seen a meaningful uptick in good contributions due to AI over the last few years. So if there's some mythical productivity increase happening, I'm just not seeing it.