First, I would like to say that I concur with Dave Snodgrass on Mid-America Avionics, they are first class. I had an S-TEC 55X installed in my 1979 Sierra. Prior to installing the 55X, I had an Century IIB. The install took 2.5 weeks and I have been flying with it for approx. 2 weeks.
The GPSS is amazing (linked to my GNS 430). The altitude hold is right on and the vertical speed is also very accurate. I have flown an ILS and VOR approaches fully coupled and they were dead-on (heading & glideslope).
The only other note I have is that Mid-America Avionics has moved from Auburn, IN to Huntington, IN (HHG). I highly recommend this unit and Mid-America.
Submitted by Jack Klute