So, which one and why?
From what I've heard, XM if you're only interested in music, Sirius if you like music and talk/sports.
Also, XM has a portable unit I guess??
I personally only want satellite radio for uninterrupted (or minimally interrupted) music, but I also like Howard Stern.
It would be extraordinarily ideal if I could find a unit that can go straight from my vehicle, to carrying it around in the gym with headphones, but I don't know if that exists...