Once I'd worked out how to get the autopilot to work properly, I've used it in various modes quite successfully - apart from once trying to use Active Pause before the latest release (haven't dared try it since!).
Last night after I'd eventually got Little Navmap to talk to MSFS I set up a flight in the C172S from my "home" airport of Newcastle with several waypoints to test it. Took off (in real time mode) and established in the climb normally, autopilot on and monitored it for a few minutes before turning my attention to other things, basically checking Little Navmap.
Suddenly the stall warning went off and before I could do anything I was almost in a spin (used to be a PPL, know the symptoms). Had to fight the controls before I could turn the A/P off (it's supposed to drop out automatically???) and retrim the aircraft which had gone to full nose up. Luckily I was already quite high so apart from overspeeding the airframe I managed to get it back under control and carefully manually flew it back to Newcastle (I believe in trying to complete a flight, even if it's all going wrong) without further incident. (The aircraft trace on Little Navmap was "interesting").
So the moral of this little story (which I hope you enjoyed!) is that, no you're not missing anything and it would appear there is still some instability in the programme. But, like in the real world, it teaches you to pay attention!