I'm looking for feedback from anybody who has had XM and Sirius in their car. What is your thought re: audio quality (compression ratio) between the two providers? I have a Saturn w/factory intalled XM. I installed a Sirius receiver (FM Modulator) a long time ago because I personally liked Sirius's content better. I recently dropped my Sirius service and went for XM, believing that I would get better sound quality with a 'direct connection' (as opposed to FM modulator). However, the compression with XM seems very high and I'm considering switching back to Sirius. Any feedback would be greatly appreciated.