As a DoubleTwist user, I have to say the product absolutely sucks. Updating a single album would resync tends of gigabytes of music to my Android device, the software provided no user feedback, and appeared crashed for a large portion of the time. I have no trouble in recommending people avoid DoubleTwist.<p>In the end, I found MissingSync for Mac -> Android syncronization and it works - not without it's quirks (mainly around compilation albums) but much better than DoubleTwist.