I dunno if this is as true for Aviation as it was 5 years ago. With Foreflight and the Stratux external GPS/ADS-B in boxes, it's becoming harder and harder to justify in panel GPS for light-sport/hobbyists/GA. I'm willing to bet that in the next 3-5 years we'll see a shift in general aviation to panel mounted "headless" GPSes that communicate with your iPad via GPS and are still coupled to a glass MFD/autopilot, but all the management would be done with an external device.