I have both XM and Sirius home units. My XM Delphi Skyfi sounds better than the Sirius Audiovox 2 tuner. More band width on XM, bigger soundstage, image, etc. I find that Sirius has a tighter play list, and has more NPR and play by play sports. XM has more music variety, better sound to my ears, and better sports talk and news. I like them both but XM is the clear winner for me.