I have Sirius personally. I love it. It was one of those random gifts that I was given from the family, (they say I am hard to shop for), that I was a bit apprehensive about, but I have absolutely fallen in love with it.
It's great for music, for news, and suprisingly entertainment. There is seriously a station out there for damn near every genre of music and the DJs seem to be good about not shoving a couple of tracks down your throat over and over. If you want that, they do have a generic 'Hits' station, but I only tune into that once in a while. (Of note, this station is one of the few that I have heard that
is still censored. Everything else is completely untouched.)
Being a pretty big News/Talk radio fan I dig the fact that there are three flavors of NPR, and a nice broad spectrum of talk radio. And while I have not checked it out much myself, they have a few odd ball chanels like Comedy and Entertainment News and such. The comedy station was pretty useless a few months back but they seem to be really pushing it as of lately in the few commercials that I do hear.
Which is another good point. Except on those stations pumped in from other media, (ABC, NPR, alot of the talk radio stuff not exsclusive to Sirius), you do get commercials. They tend to fall in the range of your typical AM commericials so they can be pretty damn annoying. It's not all a lost cause since you can get turned on to some of the other channels that are out there because Sirius uses some of that time to pimp other chanels. But the stations that have commercials I would say are in the very small minority. The majority of stations, and more importantly all the music stations, are commercial free. Its great.
Plus the little reciever I got lets me store ten tracks into the memory of the unit and it'll constantly search out the incoming stream for those tracks. If I am listening to NPR, but that old Cake song comes on some other station it'll beep and let me switch to that station to catch the song. Great for songs you don't hear often, or songs that you catch the tail end of and kind of dig. I've found alot of good groups from that feature.
I will say though that only XM has a personal device that I have seen. Kind of a bummer, as I really do like Sirius, but if that is the
main concern of yours, you are pretty much just looking at that one reciever and only XM. I've had a friend who has XM and they swear by it just as much as I swear by Sirius, so I don't think it would be too different. But if you are at all flexible in how you listen to it, check the exsclusives of each XM and Sirius. I don't know any of XM's but I know Sirius has the NFL for like 6 years or something. And I think next year it will also have an exsclusive on the NBA. Also Stern will be coming, which while not my bag should be pretty cool.
Sorry for rambaling on here, I just really like my little satallite radio.