ST,
You have raised an interesting question. I shall be interested in the responses.
Thinking about the 40+ types I have flown, I only remember autopilots in three of them, only one of which I used. That was in a Cirrus, which I flew specifically to see how the electronic systems worked.
A long time ago, I obtained an IR in a non-autopilot-equipped aircraft and I felt at the time that if I ever did any serious IMC trips, an autopilot would be nice.
Having said that, I agree with you that hand-flying any aircraft, but in particular a nice one, for example a Chipmunk, is very satisfying.