I updated my iPhone 6+ and iPad Mini 2, but have not yet updated my older iPhone 5 because it is a backup only in case the iPhone 6+ goes bad. I had just updated the iPhone 5 a few days before this new release, and it was a royal PITA as usual. I don't have a SIM card in it, and it won't update without one, even though the device is registered with Apple. I can operate the iPhone 5 without a SIM card, but updates won't finish, or rather the setup won't finish, once it restarts. That is just stupidity on Apple's part as it says the phone isn't registered when it is. I hate having to take my iPhone 6+ off line, turn it off, remove the Otterbox case, remove the SIM card, then place it in the iPhone 5 just to do an update.

ETA: Apparently Apple fixed the no SIM card issue with update. I just updated my iPhone 5 which does not have a SIM card installed and the update finished without issue this time.