Capt Pit Bull, yes they do, I defy you to fly any procedure as accurately as an autopilot and if you try have any capacity left for the real world on a dark and dirty night and if you try it why?
411A - 37 yrs 16000 hrs. Trainer. I have flown all types with and without autopilots. I have never had to operate glass cockpit aeroplanes with all autopilots u/s, if I had to fair enough, but in 15 yrs with my current airline we have not had a single occurance of multiple autopilot failure. I have witnessed many near misses and crashes in simulators because guys cannot operate the aircraft and revert to manual flying. I have never seen a correctly operated flight system crash the aircraft. We have cases by the dozen where aircraft have crashed because the crew screwed up, this looks like one, engage the autopilot in hdg and alt and you won't hit the sea!
Master Green - 777's ? you're in the DC3 era.