My buddy had XM on his Ford Lightning.
Honestly, it was pretty cool at first..kind of a novelty. But, we both agreed that there is SO much programming on those things that it is almost too much...gets kind of old hat after a while.
I guess you have to determine if you are a.
Radio person..then XM might be awesome for you
CD Person (Which is what i am)..so XM isnt that appealing to me.
Concept is good though.
Even though Both XM and Sirius are doing crappy (as a business)..i know that Sirius is the worse of the two (From a profit perspective). This might result in some volitality in the company (Aka..company folds and you have a subscription to dead air!) ..not sure if there is a quality difference though.