I took my girlfriends upgrade to snag my 6+. Everything went smooth until I went to activate. Hopefully this post will save someone a bit of a headache. First it was a huge hassle to get my number transferred over to the nano Sim. Then I spent three hours on the phone trying to get mobileData working. It turns out that if you had a grandfathered unlimited data plan they need to transfer you over to a voice over LTE unlimited plan. Plus they need to add a bunch of other things to the account for it to work. Still only seeing 3 bars of lye but at least it is up and running.