I personally have XM and even though it is PART owned by clear channel the quality is pretty high. I forsee this battle being like the Beta/VHS battle even though Sirius might be a better choice they arn't going to last. Sirius just dosn't have as deep as pockets as XM and its going to be a long arduous battle for supremecy and I don't think Sirius can outlast XM. Besides the high angle eliptical orbits of Sirius's satelites is a less reliable signal than XMs geostationary dual satelite method.

Bryan