"Craig Prouse" wrote:
It seems like a heading reference might improve the ability of an
autopilot to maintain course precisely or at least reduce any
tendency to weave or hunt while bracketing the course. Would
anyone with direct experience like to offer a comparison?

I can only testify about my S-Tec 50, which is the same in this
respect as the 20 or 30. It works strictly off CDI deflection and rate
of turn. I don't think there is room for improvement. Using the GPS
CDI, once established on a track, it will maintain a xtrack error of
just a few feet without hunting. That is with the autopilot set to
"approach" sensitivity and the GPS CDI scale set to one mile.
--
Dan
C172RG at BFM