I normally do an OTA iPhone update, but I tried to update my iPhone X via iTunes and got the error about needing to update iTunes.
I'm glad I did it this way and was alerted to the issue, because it was only a 1 in 10 chance that I would have gone this route. Then I'd be forced to roll back asap to iOS 11.2.6 before too late, and before I'd possibly wiped over my 11.2.6 backup.
We have too many iDevices to re-download apps on each of them in case of a restore or a re-download - Apple only allows an Apple ID to have 10 devices authorized to re-download content, and we have 5 iPhones, 5 iPads, and 5 Macs in my 7 person family.
So, we set it up so that 5 Macs and 5 iPhones can download or re-download content = 10. Then we have to side-load apps and other content onto the iPads via the Mac's iTunes (me, my wife, my kids, & mother-in-law).
If I upgrade to iTunes 12.7 then I cannot install any more apps on several of our devices, which must download them directly via WiFi, because they're not all authorized!
Also, with so many devices we cannot afford the bandwidth when (1) each device has 10-30GB of apps and (2) all of them need to be updated via WiFi each time instead of via iTunes with just one download required (in iTunes). That's why we stayed with iTunes 12.6.3.6 on each of the 5 macs.
I wanted to test it but I can't get Configurator 2 to work on the iMac that sync's most of my devices right now, because AC2 has been accidentally updated at some point by my wife, while iTunes hasn't been. And so I don't know how well AC2 will work to save apps on the hard drive (which occurs when you update apps I'm told, and then I'm told if you want to keep an archive of old apps that you have to copy that to a backup folder so that you don't lose it later). I've had to roll apps back in the past, and I have several years worth of old app backups saved for just in case (>500GB on the NAS).
How well does iTunes 12.7 + Apple Configurator 2 work to do what iTunes 12.6.3.6 has been doing in the past?