Our Tahoe came with an XM antenna & compatable radio factory installed. So we couldn't resist and went ahead and activated the service.
I LOVE it!
The music stations are commercial-free (the other stations, like BBC, CNN, etc) do have commercials. It works everywhere , with no fuzzy reception. We took it up to the boundary waters a couple weeks ago, and usually once we get north of Duluth we start losing radio reception, and by the time we're even remotly (100 miles) close to the lodge we go to, there is no radio reception at all. With XM we had our full selection of stations the entire way.
Also driving home to my parents farm I drive through a couple areas where the FM radio reception sucks. With XM, again, clear stereo sound!
Plus, XM just started traffic & weather for major cities nationwide, so we can get instant traffic reports whenever we want, without having to listen for 15-20 minutes on other stations. (Traffic reports are seriously necessary in Chicago.)