I learned to fly in an Enstrom F28A. No correlator. It was easy to learn, and I figure if I can learn it anybody can. It became very natural to twist the grip as I pulled or dropped collective, also had to pull in a little more for a left pedal turn and roll a bit out for a right. I do agree there was no automatic mixture control though we always left it rich and stayed low. I have a little time in a Schweizer 300CBi, and that sure looked like a manual mixture control to me. I'll check with one of my buddies and report back if I'm wrong.
-- IFMU