sync/upload music? I see in the description that it "requires" Windows Media Player. Can you add music to the player through iTunes? Or better yet, with Google Play (in which case music would be downloaded from Google Play directly onto the player).
no syncing needed. using plain old windows explorer file system, you drag and drop. to your computer, it appears the same as any other usb storage device. I believe you would have to keep an mp3 file on your local system to drag and drop it to the player, the cloud auto-download to the device may not work the way you hope.