I sincerely hope Dave takes the criticism in the constructive way in which it is intended.
The Lockheed system, as fitted to CL475 (and initially to Cheyenne, before DOD spec increased disk loading to give dynamic problems) was exceptionally clever. I can only begin to describe it's subtlety:
Underneath the rotor, as part of the swash plate was a large gyroscope. Being rigid, the lead angle to plate was less than 90 degrees (~30 I seem to recall, since even "rigids" have flex and a floaty helicopter inertia). The cyclic was connected to this gyro via springs, with an additional lead angle of 90 degrees. The gyro tried to follow the horizon, and effectively flew the helicopter. Pilot cyclic input caused the control gyro to precess (in same way as teetering swash plate), by being 90 degrees lead. The springs were really just there to provide a sensible movement for a given input force.
If you think about it, the chopper will always try to fly in trim with the gyro. The pilot is thus directly controlling the pitch and roll rate of the gyro with stick position, hence directly controls heli pitch and roll rate. I just can't think of a more linear system, in all flight conditions. I was hoping Nick Lappos (ABC man) might like to comment on his thoughts about this system, but respect if he prefers to steer clear of this thread.
It would be easy to take a lead off the gearbox to drive a much higher speed gyro, thereby reducing required mass. The cyclic would go to the gyro, and the gyro to the two swash plates. Some additional mechanical complexity (which i appreciate is bad), but with FMECAs and design calcs/simulations a very easy bird to fly.
Mart