The Quick Start does work. I used it for my phone. But check with your carrier’s migration process before you start. There may be things to watch out for.
For example, Verizon’s procedure asks you to disable Find My on the old phone and then power it off. They want you to perform a manual setup in order to get the new SIM card properly activated. When you get to the part of the setup where you are asked if you want to restore an old phone’s backup, you can power it on and (allegedly) use QuickStart to transfer the data from the old phone.
(I say “allegedly”, because I didn’t follow Verizon’s directions and therefore didn’t experience this part of the procedure. I did a QuickStart immediately after powering on the new phone. Everything transferred, but the new SIM card refused to activate. I needed to involve Verizon’s phone support to retry the activation, which did work.)
You should also note the following:
- If your iCloud storage isn’t big enough for a backup, Apple will temporarily grant you enough backup space to complete a device migration. According to Apple Insider this was announced in June of this year.
- If you don’t want to use iCloud backup, you can still make a backup to any Mac or PC over a USB cable (or via Wi-Fi). On PCs and older Macs, you do this via iTunes. On newer Macs, you do it via the Finder. Either way, be sure to create an encrypted backup - this will cause it to back up secure data like saved passwords.
- But you should definitely try the QuickStart first. It’s fastest and easiest. You should definitely make a backup (via iCloud or a computer), but don’t set up the new phone from that backup unless QuickStart fails.