I just wanted to chime in with the other side of the coin. I used the XM flavor every day for over a week while my car was repaired. I don't own sat radio, and I don't want it.
The fact is that to anyone seeking high quality audio, sat radio is a step backward, or possibly a step to the side. It is definitely not a step forward.
It is billed as "digital quality audio," but in reality that means less-than-cd quality on the best channels, and less-than-fm quality on the more obscure or localized channels.
Now, Sirius might be different than XM. Actually, they are. Sirius uses an AAC-based codec that runs at, as far as I have read, 64kbps. That's not a bad bitrate using they type of compression they use, but I would doubt anyone who listens and determines it is CD quality.
XM uses a different codec with variable bitrate depending on the station. 80kbps is their max I believe, with less-used stations running 40kbps and news and talk running at an unacceptable 32kbps (AD Radio broadcasts at 64kbps, beating all but the most popular XM stations in terms of frequency response, and AD Radio doesn't always sound so good).
The problem is that the sat providers keep trying to cram more and more audio onto their limited amount of satellite bandwidth, and quality suffers as a result.
It is the same situation as digital cable. Those who believe the hype pay extra for digitally-delivered cable that actually has worse picture quality than plain old analog cable. Yeah, there may be more channels, but you can still only use one channel at a time. Quality wins for me over quantity every time.
The other thing that surprised me about sat radio is that it has commercials and DJs. The DJs use their same over-compressed, half-inch-from-your-eardrum setup, and it is still annoying. I don't need people to talk to me over the radio if my receiver tells me the song that is playing. What more do you need to know?
Another thing that annoyed me: over a week of blues channel (mostly)-- not one BB King song or Buddy Guy song. Pathetic. But they did play a lot of songs from some unknown soulless blues band du jour. I wonder how many CDs that sold for them. Advertising is still advertising even if it is done under the guise of being informative, and at the expense of true quality.
And last, if you're not in a major-market area with FM backup, and you happen to have trees near you, expect drop outs. XM is useless in Savannah until you get out of the downtown area.
Anyway, sorry, I'm not a big fan.
Mike