Setup new iPhone via iCloud backup. Enter email address + password. Phone says the password's incorrect for someone else's email address.
I set my wife's tonight from an iCloud backup. Horrible experience. Took 3 times.
Mine's all good with iOS 10 'cept Apple Pay's gone. Apple suggested back-up/restore so got on the Harley for some therapy!
the apple rep said, "maybe one of your friends downloaded something with their account one time" and to just go ahead and skip that step.