My biggest complaint about Sirius is the content. I have XM in my truck, and I hardly ever listened to anything other than XM. Now that I have Sirius in my E90 I find that I hardly ever listen to it because there is never anything on that I wish to listen to. There are fewer channels and the few they have seem to never play what I want to hear.
2008 Sparkling Graphite 535i
2009 Land Rover LR2
2003 Porsche 911 Turbo (SOLD)
2006 Jet Black 325i (SOLD)
2001 Bullitt Mustang (450rwhp - SOLD)