I don't have it, but I'm considering it. It's a couple hundred bucks for the reciever, and $10/month for the serrvice. There are a couple different units available, so price will vary. They are built by quality names like Pioneer, etc. Not Audiovox/Kraco. You can either hardwire it or use an FM modulator, where you tune a freq into your FM radio and listen through that. Cost will vary as to the set-up. The antenna is a special antenna. I've seen a thick, short one and a shark-fin type. The shark-fin at least is a magnet mount, I don't know about the short, fat one. I would assume you would loose transmission in tunnels, etc. Supposedly, clouds don't block it like it can with Sat TV sometimes. I dunno about that either yet.
There's something like 76 channels on it. They're grouped to the genre. BBC has or supposedly will drop it's Short Wave service to North America because they are broadcasting it on XM. There are a host of other types of music, news and information. Some have commercials, some don't.
I don't think it would be worth it if you remain in a local area that has good radio coverage, and you get good stations. I think it would be perfect if you're on the road alot, or in dead areas, or in small radio markets where the only station you get plays music you can't stand. Sort of the same reasons really to get Cable/Sat TV. If you spend a great deal of time in your car, it would probably be worth it. One big advantage is if you drive a great deal, you wouldn't loose a station, then have to find another. You just can listen to the same channel from one end of the country to the other.
I haven't been completely sold on it yet. I haven't completed looking into it yet either. I need to really check out details on it, but it is interesting.
Ross