I won't have anything to do with Bendix King due to their terrible customer (and potential customer) support. I tried for weeks to get wiring information from them when I was considering their ADS-B transponder for me and a friend. No joy. Contacted their rep at Airventure. Still nothing but bureaucratic excuses, no wiring diagram info.
One of my A&P friends at KHEF just regaled me with his experience of Bendix King losing (multiple times) transponders he sent in for repair. 6 months to get one of them back. Horrible, non-responsive bureaucracy.
I've observed vastly superior customer service responses from both Garmin (530W troubleshooting, GDL-88 install) and Advanced Flight Systems (AF-4500 install and maintenance). Stark Avionics provides incredibly fast, thorough support for avionics they sell, in my experience. From what I see on VAF, Dynon is very good, too.
RV-10 N31TD - 1250 hrs
RV-6A N47TD - 1100 hrs (sold)