Apple offers several methods to transfer settings from an old phone to a new one. A particularly promising sounding one is the "Quick Start" approach, which begins promisingly enough with some cool automatic recognition of the new device. But things pretty much end there. Nothing about actually transferring seems to be any different than any other method: one still has to restore from either an iTunes or and iCloud backup as far as I can tell.
What does the "Quick Start" method actually transfer? Is restoring from a separate backup still necessary to complete the process of transferring settings, apps, and keychain info from the old iOS device?