I would wait until they launch their new satellite in a year or so. It will be in A geosynchronous orbit like the XM satellite, it should improve bandwidth, and improve reception.
I have noticed the Stern sounds great all of the time, during the morning when his show is live every other channel stinks. I assume this is their adaptive bandwidth system at work.
At work when streaming with the premium connection the audio is more consistent, and does not suffer like the radios do