Gooomz -- We have had the Polk XRT-12 for over a year now, running through a 990/755 set-up to DefTech speakers. My wife and I agree the sound quality generally is very high, but perhaps not full CD quality. This applies to the music channels; certainly highly compressed voice channels (such as weather/traffic stations) are noticeably inferior. The other issue is location of the antenna. In our case, sometimes the signal drops -- not a deal-breaker by any means.

We really loved XM at first, but then it made some station changes and eliminated our favorite station (a Latin jazz one called Luna). Hope this helps.