If you own a GNC 300XL or have flown with it extensively in the past, I am curious about any useful feedback you might have. Any high points, low points of the design? How is the usability? Does it feel just like the old KLN 8x or 9x series units? How about DB updates? Thanks in advance Lou Edit: I posted this question specifically in this forum because I am looking to maybe have to use it for IFR.