I find the USB audio to be somewhat hissy and/or scratchy on occasion, but it still sounds better than Sirius. BT streaming audio sounds about the same as USB, which leads me to believe that the DAC in the 130 is crap. I've been happily(*) using the AUX jack.
The biggest problem I have with USB/BT audio is the lack of playback control when using an iDevice. There's no way to temporarily pause the audio (bank window, toll booth, drive through).
* I sure wouldn't mind having that Connectivity $ back in my pocket.