Textron Aviation has adopted Garmin integrated avionics suites for most of its new production airplanes. Surprisingly, though, one of its most popular and long-produced models, the Citation XL/XLS, still comes off the assembly line without the Garmin treatment. But with about 700 of these models already flying, Garmin saw an opportunity to offer a retrofit, and now owners can replace their original Honeywell avionics with a modern G5000 flight deck. AIN editor-in-chief Matt Thurber goes for a flight to experience the setup.