Hi , I have a VFR RV 6 with a AV 30 E & am reasonably happy with the instrument however I was considering either coupling a Garmin 660 or getting an Avmag( external magnometer) to use for DI. I’m aware that the GPS will only give GPS track & that the Avmag will only give heading. Just wanting an opinion on either off someone who has used either system. The Avmag is considerably cheaper but of course the GPS gives me more features. I currently use a device & flight planner for guidance but find that the standard DI on the AV 30 needs regular adjustments to align to the compass. Thamks .