We have XM and the Polk XRT12 tuner, plus XM in one car. I agree with Otto that for background music it is good (and I think with the Polk it sounds about as good as it is going to get) and near-CD in most cases, but it is not lossless. The plus side is the huge seletion of music played. A downside is that XM continues to adjust its channel and music mix, and has eliminated some channels (such as a Latin jazz one) that were our favorites. We now tend to use our Sonos system more (lossless recordings) for critical listening at home and the XM in the car.