I have 5 XM Radios...
1 in the XFR
1 in the Sierra Denali
1 in the MAZDA 3
1 in the Garage
and a portable I share in the YAMAHA Jet Boat and at work.

I took a station listing for each (XM & Sirius) and looked for the music, etc...
that I liked...
FOR ME...XM Won.

It's like which is better...
Ford or Chevy???
XBOX or Playstation???
Each has something different to offer...and we each have our own tastes!!!

BOTH ARE GREAT!!!