I have a new 15 Pro arriving Friday. I wonder if I should update the existing 12 Pro before doing the transfer to the new phone. My inclination is to NOT do that, in case there are any hiccups in the transfer.
Additionally, I’ll be taking a long day trip the next day, so I’m strongly tempted to not do anything with the new phone, or at least to not activate it on the cellular network.
Thoughts?
I would generally recommend that you do update an old iPhone to the latest version of iOS before transferring to a new iPhone just in case Apple made any last-minute changes behind the scenes for old phones to improve the transfer process. But it’s probably not that important either way.
But I agree strongly that you should NOT switch to a new iPhone the day before taking a long day trip. That’s just asking for trouble. Make the switch when things can go wrong and they probably won’t. :-)
100% agree with Adam’s advice. Wait until after the trip before using the new iPhone.
I’m actually considering NOT updating my 12 mini before the 15 arrives on Friday. If there’s any serious issues with 17.0, that 12 mini would allow me to go back to safe territory while Apple prepares a 17.0.1 or 17.1 fix. That 15 could just stay in its box for another couple of days while the fix is prepared. But if I update the 12 mini first, there will be no bridge back since Apple goes out of its way to prevent downgrades.
I’ll admit I’d be updating that 12 mini as @ace suggests if I had more faith in Apple’s software QA. But after the way certain more recent updates have gone (both macOS and iOS) with serious issues going unnoticed by both Apple and the entire “beta tester” community, such that Apple then had to pull updates or release emergency updates to the update, well, let’s just say I have lost faith to go all in with them. These days I always try having a fallback (or two). 
The update is live by the way (1:20 pm on 9/18).
I’m going to jump in right away. I’ve never had issues with updating stuff immediately – anecdata, I know, but what the heck.
My thought is that it does not matter. I have done restores from an older version of iOS to a newer, and it always worked perfectly fine. (That said, I generally upgrade my older phone first, but that’s mostly because I rarely get a new phone on launch day.)
As for taking a long trip the next day - again, it probably should not matter, but there have been weird issues in the past with brand new phones shortly after launch day with weird issues, so I’d say your temptation not to transfer until after you return from your trip is probably the best way, just in case.
I’m also updating right now, mostly so I can have watchOS 10 on my Ultra.
My backup phone is an iPhone X, which can’t get iOS 17, so my backup S5 watch for the first time I will keep on watchOS 9 on the off-chance my iPhone 13 Pro fails and I need to step back to the X.
And…updated! No problems.
What if you can’t update to the new iOS because the old phone (iPhone X) is unable to accept the iOS update? I will be receiving the new iPhone 15 sometime in October but hoping I won’t have transfer trouble.
You most likely won’t. iOS migration is usually quite flawless and in general there is no inherent issue updating to a new iPhone 15 running iOS 17 from an iPhone X running 16 or 15.
It will work fine…just make sure that the X is up to date before doing the migration. Personally…I’ve always made a backup right before activating the new phone and then updating from that backup…IIRC there’s a way to have them both on wifi and do a direct phone to phone migration but I’ve never tried it and I might be misremembering things as it has been 5 years since we migrated phones. The fact that iOS 17 will likely be the last one our Xs models will get (along with the battery issues and better camera and faster processor) is one of the reasons we’re upgrading this year (well, that and also we just want to upgrade). I’m with Adam on this one.
The only glitch I’ve encountered is trying to activate the new phone’s SIM card (Verizon network) at the same time as trying to migrate an old phone to the new phone directly (using Bluetooth/Wi-Fi). It glitched and failed every time.
We “solved” the problem by setting up the new phone without migration, in order to get the SIM card properly activated. Then we backed up the old phone to iCloud, wiped the new one, and restored it from that iCloud backup. That worked.
As far as I know, this is what Verizon recommends for this. I have these instructions from back when I activated my 13 Pro a couple of years ago - which includes instructions on how to initiate the Quick Transfer / Migration after the activation. IIRC the instruction too have the old phone powered off (after disabling Find My) before starting the activation of the new phone was a key step.
Yeah, we saw that article. It was the transfer (at step 11) where everything glitched and failed. The SIM activation takes some time to complete, and stuff fails in creative ways if it hasn’t happened yet.
We had to skip all migration and let it boot up to normal operation with nothing but the default apps/configuration. Wait for the SIM to become fully operational (see the 5G icon, make a few test phone calls, etc.)
Then go back to system settings to wipe the phone. Then restore from the backup on the next reboot, which succeeded because the cellular network was fully functional at the start.
I pushed the 12 to the new operating system, no problems. But I’ll wait and do the transfer to the new phone after I get back from my trip.
And I note with -extreme disappointment- that I STILL have to enter the phone passcode EACH TIME I connect the phone to the laptop. That’s a mis-feature that I was hoping would be fixed.