When Itunes sync the music to the iphone 6 it sync a lot of songs each time (always different) like 400, 200, doesn't matter if i just put 1 new song, and it takes a long of time like 1 minute each song, Also the pc doesn't recognize my iphone, i plug the usb and nothing happen, or the pc told me it doesn'tt recognize the phone. sometimes it just charge the phone but it doesn't appear on itunes or impactor, but when i plug the cable to the power plug it charge the phone normally, sometimes the pc recognize the iphone (on that moment is when i try to sync the music but i don't know if that's the reason of the slow sync) but it discconnect if i receive a notification (i thinks it;s because the vibraation).
