Somewhere there's a thread for Satellite radio. Check that out for other people's opinions.
I don't know anything about XM.
But I can tell you about Sirius. Many people have bought it over XM simply because of Howard Stern. I haven't cared much for Stern since sometime while he was on broadcast radio. I chose it because it claimed that it would broadcast all the Buckeye games. But that was retarded for me, since I would just watch all of the games from inside the 'Shoe or on TV. But I have used it to listen to NFL games. I think it advertises all NFL games.
Sirius has a couple of music stations that are pretty good, and that's saying something coming from me, because I am VERY picky when it comes to music. And you can have it alert you when specific artists/songs come on another channel, so you can zurp right to that station, if you want. I'd imagine that XM has similar features.
Sirius also has ESPN radio, which is okay, if you feel like hearing a bunch of yutzes who enjoy speaking about crap. I think one of the coolest stations, though, is the one that has Rivals Radio. For three hours a day, five days a week (or more) they talk about nothing but college sports. And 90% of that is football. Awesome.
I don't know about HD radio. All I know is that when I'm in someone else's car, and listening to his radio, I realize how spoiled I am with my Sirius.
) I almost never lose my reception, the only time I did was driving through the mountains of Pennsylvania and that was only for a few minutes. I work in an all brick building with only a few windows so I have my antenna ran outside and sitting on the fire escape. If you decide on sirius look into the Stilleto unit, it is a portable unit much like a ipod. It is expensive but you can take it anywhere.
