I have had XM since it first came out. Bought a car and home kit.
I agree the sound is mediocre, but the fact that I can travel in different provinces and states, while listening to my same rock stations is key.
Since XM & Sirius merged I noticed immediately that the talk (chatter) increased, which annoys me.
However I'll still renew.
When I want quality sound, I pop in DVD's for the 5.1 surround sound experience which is far better than FM, Satellite, CD, MP3 or cassette.
(obviously the cassette is gone in the GC, but still have it in my Pacifica)
Now if only I could get my turntable to stop skipping when I'm driving
I'd really have some quality sound)