My Century 41 is 41 years old and though it still works, I am considering adding to the Aspen 1000 PFD with an upgrade to the Aspen 2000 Max and eliminate the steam gauges. I am anticipating replacing the AP sometime in the near future but the GFC500 is not compatible with the Aspen, as I understand it. I am wondering what other K drivers may be using apart from the GFC500?