I'm curious about satellite radio, can you help?

I'm thinking about getting satellite radio. I'd like to know what pros and cons you fine people can offer. Thanks in advance

there is no where to mount the unit in my car without making it look as if Rube Goldberg did the installation.
And I cannot justify the cost of replacing the AM/FM/CD unit.

I live in a redwood forest.

My tastes are probably to far outside the what they consider the mainstream anyway.

2, 2, and 2. HAHAHAHA. Not really what I expected.

I wanted Sirius because it looked more to my liking. I ended up with XM for several reasons. It has Air America and I live in Kansas, that should explain that. My husband has a set up in his car that is XM ready and he was complaining when I was thinking of Sirius. There is a deal right now that if you buy XM you get a free Roady and I can take that and set it up in my barn so when I work I don't have to listen to the crap that is called radio around here.

I am very happy with it, VERY happy.

sports...Sirius has NFL, NFL Radio, NBA, NHL (maybe someday), English Premier League, approx. 25 select NCAA football/basketball teams. Nascar beginning in 2007.
XM has MLB, Nascar till 2007, Big 10, ACC, PAC 10

politics...XM is the exclusive satellite provider of AAR.
Sirius has Sirius left and AAR only till July. Some of the
programs on Sirius left are pretty decent though. Thom
Hartman, Stephanie Miller...Alex Bennett.

music... XM probably has deeper play lists, thus making their fare
a bit more eclectic.
Sirius music stations are more logically organized and
much truer to the station theme.

misc.... if you prefer a morning drive time morning zoo type of
format Opie and Anthony is on XM.

Sirius has Stern beginning in Jan.

I have no experience with XM customer service but Sirius customer care reps are terriffic, in my dealings with them. Truthfully, if I could afford it, I would like to have both. Having to choose one. I go with Sirius simply based on the NFL. I have to work on Sundays and I much prefer listening to games than following scores on ESPN radio.

That's the kind of response I was hoping for. I can read their websites all day and never get this kind of information. Thank you!