In certified aircraft autopilots are not renown for reliability.
Any reports of reliability on the various autopilots builders put into their homebuilts? And how much use of said aotopilot?
The following units have flown in my RV-6:
1) Navaid, ~400 hrs. Control head was returned to factory once for defective turn coordinator display. Operationally, the device was about as good as can be expected from an analog system using low-cost components. The newer digital systems offer far more features and reliability. The servo (~800 total hours) has been trouble free and is still used with my Trio Avionics EZ-Pilot.
2) TruTrak AlTrak, ~300 hrs. A very simple system that operated as designed with no problems. Was replaced with Trio EZ-Hold because I wanted climb/descent/target altitude features.
3) Trio Avionics EZ-Pilot, ~400 hrs. Because I have flown this system since its earliest days, I worked through some minor issues with very early software. The software released in the past couple of years has been flawless and there have been no operational issues. I have flown three versions of this device, all with different displays.
4) Trio Avionics EZ-Hold, ~250 hrs. Software and hardware has been flawless and I have flown EZ-1, EZ-2, and EZ-3 versions of this device along with several different generations of software.
All in all, these systems have been rock solid. The current generation of digital autopilots are amazing devices especially considering their features and prices.