Sirius does look pretty cool. I was at the Dodge dealership the other day getting my Mobil-1 change in my daily driver, and they had a 2008 Caravan sitting there for folks to look at while they wait (service center is separate from main dealership property). I got in the vehicle, and it had Sirius (couldn't play with it because it had no signal there in the garage), but from looking at the brochure I learned that they now do video broadcasts (for kids stuff) of select shows from three different kids networks. So they're actually expanding into other areas whereas XM seems pretty stagnant at best. In fact, one of my favorite XM stations was pulled from the air last year (online only now), so I understand your irritation with that.
I think satellite radio is really cool, but when they started playing ads on XM, it really made me mad. I've listened since early 2004, and now I won't listen to any station with ads on XM, a service that I pay handsomely for. Does Sirius have commercials on any of their channels? I don't care about NFL or Stern on satellite radio, so that content is irrelevant to me.
I currently have 4 XM tuners: 1 in each of our 2 vehicles, one in a home stereo system at the house, and one in a mobile/boombox setup for my mother-in-law who loves the 40s / 50s / 60s stations.