Sirius has Howard Stern; XM has Snoop Dogg. At one time, the two were competitors, but have since joined in a corporate merger. Because the two systems are incompatible, Sirius XM broadcasts most channels to XM and Sirius subscribers. Both feature more than 100 channels of music, news, sports and entertainment, and are being factory installed in hundreds of new car models. Take a look at Sirius vs. XM to see more about the merged company and learn about its services.