Trio
I have a Trio autopilot in my RV-6, and the gains are all easily set by the user, and can be set inflight. I recently encountered some pretty heavy turbulence, and the autopilot was "over-reacting" a bit. I was able to easily adjust the gains inflight, and the autopilot handled the turbulence extremely well after that.
My aileron servo is installed in the wingtip, using the Trio mount. Very easy, just remove the wing tip and install.
Great support from the company, as well.
As Sam said, just another data point.