For what it's worth, I have experimented with iTunes playing through the 2150 using the USB port and using an Apple Airport Express which I connect w/RCA connectors into the 2150 Video ports. My conclusion is that the USB connection is far inferior to the other method.

I tried different PCs using lossless and loss formats and in every case, the USB connection sounded inferior. It doesn't make a lot of sense to me that a wireless connection should sound better than a wired one (using the same source), but I can tell you with certainty that it did in my case and I am perfectly happy with the sonic quality.

That said, I still listen to vinyl and CDs when I have the time to just sit and enjoy, but when I use music as a background for other activities, the Airport Express is a great solution from my perspective.