Originally Posted by KRL

Just installed XM, too, so now I've got both. Comparing the two, XM's sound quality is much more CD and high end stereo like, and also crisper accoustically than Sirius. Sirius, though still higher quality than regular FM, doesn't quite have the same punch.

Also, Sirius doesn't have the terrestial repeater anywhere's near as big as XM, so Sirius's signal drops like crazy, like everytime you drive under an overpass and the sat signal is blocked. Whereas XM's network is so big, you're able to hear XM inside a building, by picking up the ground based repeater transmitted signal.

I got the Pioneer AirWare XM2GO model, so it's completely portable and can be moved from car, to home, to carry with you quite easily and its a really sharp looking unit. Its also got built-in memory so you can record up to 5 hours of XM music for replay in non-live mode.