I currently have an Stec 30 autopilot. I want to upgrade to a full function digital one. I can get an STec 3100 and keep my existing servos to save money, but to get full function including altitude preselect, I need a baro source. The most obvious choice to me means adding an Aspen ProMax which will probably be a total of around $30,000 installed. or I can get a Garmin GFC500 with dual G5s which will probably be around $22,000 installed for similar functionality. Navigator is a Garmin 530W. The Aspen probably has slightly more functionality, but I have friends who have had problems with them (perhaps the Max will make them more reliable with built in AHRS). Garmin has redundancy. I'd sure appreciate opinions to help me work through this pleasant dilemma. Thanks.