I felt a little bit bad tearing all that stuff out, but just a little bit... the XLS can't do LPV approaches, the audio panels were getting old, and of course I will eventually need ADS-B.
When I went to a Garmin panel, I saved a few hundred pounds (not insignificant given the 980's low gross weight), and also was able to get rid of the pedestal between the pilot seats, which made getting in and out of the cockpit a pain. I also got inflight weather, and the aforementioned ability to do LPV approaches (which I use all the time now).