I'm running XM and Sirius receivers side-by-side for audio comparison. XM unit is an XMPCR; Sirius is an Audiovox PNP1. Both of late 2003-early 2004 vintage. Here's the scoop: 1) XM runs about five seconds ahead of Sirius for the equivalent channel. This makes A/B comparison of the same passages easy. 2) For these particular units, the PNP1 is the clear winner in audio quality, with superior crispness and separation. 3) Those frequent pauses in the music, fr..equent p..auses, come through on both signals at the same point in the track. Not at the same moment in the receivers. So they aren't caused by weather or antenna placement, by interference or by any problem at the satellite uplink or downlink. They're more likely related to a problem with the massive servers that process the music. The audio isn't truncated when the receiver goes silent; it picks up right where it left off, mid note or mid syllable. Any thoughts or experiences on either of these two topics: Sirius vs. XM on an A/B switch, or the frequent stutters and pauses in the audio, particularly bad since the channels merged. Has everyone heard the pauses? Do they turn up on talk programming, or when the jock is speaking, or only during music passages? I'm finding them intolerable after years a subscriber to both services.