Maybe I'm doing it wrong (using a variety of models on GitHub Copilot) but in complex tasks I often find that they give me code that doesn't quite compile (often due to lifetime errors, sometimes other issues)

That narrative is still popular with LLMs themselves. If you ask an LLM whether it can code Rust, it will tell you that it can but not very well.

They're good at web languages, python, and C/C++. As far as I can tell Rust works if you're already good at Rust and you can catch its screwups and strange architecture choices quickly.