I've been playing with it recently, and I find unless there are very clear patterns in surrounding code or on the Internet, it does quite terribly. Even for well-seasoned libraries like V8 and libuv, it can't reliably not make up APIs that don't exist and it very regularly spits out nonsense code. Sometimes it writes code that works and does the wrong thing, it can't reliably make good decisions around undefined behavior. The worst is when I've asked for it to refactor code, and it actually subtly changes the behavior in the process.

I imagine it's great for CRUD apps and generating unit tests, but for anything reliable where I work, it's not even close to being useful at all, let alone a game changer. It's a shame, because it's not like I really enjoy fiddling with memory buffers and painstakingly avoiding UB, but I still have to do it (I love Rust, but it's not an option for me because I have to support AIX. V8 in Rust also sounds like a nightmare, to be honest. It's a very C++ API).