Just set up a new iPhone 8+ for my wife (she likes the home button). I tried Migration for the first time. Migration just seems to go thru some basic setup information, but then you end up at iCloud restore from backup. And I have to admit, I have never had a problem with restore from iCloud backup.
I remember some saying that the iCloud approach was better than the iTunes approach since all the Apps are downloaded fresh. I have also, in the past, done setup as new, but really have not seen a difference. But, in all due respect, I have not had a problem yet either--If I do setup as new would be my first approach to try fix it.