The USB freezing/skipping is happening to me as well with an Edge Limited that I just picked up on December 28th (ordered in mid November). I've got the latest build of the Sync system as well.
It doesn't happen often thankfully but it does happen. I have no fix other than to get annoyed and go back to the song I was listening to.. I haven't experienced any of the lockups, Sync reboots, etc, that others have reported so I'm hopeful that the Sync update addresses those.
I've also noticed that the Sirius radio will sometimes freeze for a second or two and then come back. Usually that happens when you go under a bridge or something but this seems to happen in the wide open as well.