My STEC30 with GPSS is very good for such a simple AP, but it doesn't do well when you get garbage vectors, tight turns and a "keep your speed up" like I got the other day from NorCal going into KMRY, with two layers of clouds to deal with, after he'd already vectored me across the approach to get in a molasses slow Cessna, then 10 miles out to sea to get in an airliner. Those are the times where you just hand fly the plane down, especially knowing you're on final and the only comm change you are getting is tower, which you should have had in when you checked in with approach.
But yeah, I really enjoy having the AP to keep fresh in cruise and also to handle approaches where the workload is getting obnoxious.
Some jag here decided to be a clown about that once though.
That wasn't autopilot
They usually don't ask questions till people are a mile off, even on V186. I was on that and some poor guy in a Bonanza got asked by ATC if of his VOR was off, cause he was about a mile off. He said "it's not the plane, it's me." He would have been in VMC too, though over the top of a pretty solid layer. She was nice to him. They do get really funny with altitudes though.
It is definitely a good idea to magenta line that route though.