For me it has been a very mixed experience. I've had LLMs spit out 2K loc of relatively tricky code that worked the first time out of the gate. It compiled and ran and passed every test I threw at it. I've also seen them deadlocked on trivialities over 100's of toolcalls until I couldn't look at it anymore, stopped the session fixed it myself and continued from there. It's like having an idiot/savant with a weird mix of cleverness and sycophancy thrown in.