So, I just turned in my leased 5s, and got a 6 Plus. Everything restored just fine. I wanted to perform a sync, and backup afterwards for good measure. During which right in the middle of it I get message that the backup or sync cannot discontinue, because the iphone has disconnected.....but it hasn't. I watched it the whole time, it never lost connectivity to the cable. These are after market cables, but I've never had an issue like this previously.