I can tell you from my experience in dealing with the guys at X-Com for the past 6 years they are hardworking, dedicated aviation "nuts", & electronics experts. I'm not trying to bash anyone here, but I can tell you 95% (or more) of problems caused by specific installation flukes, or user mistakes. Before sending the unit back, read the manuals and be critical of your intallation, antenna, leads, connections, ect. Every radio is personally tested before it leaves the factory.
As you can see, these guys will answer your questions and stand behind their products. There is a US service center in Tea, SD, and radios are sold by Aircraft Spuce (and many others) and installed by many OEM aircraft manufacturers (Light Sport) in Europe.