@caseyliss I read that the FIRST thing the new phone does is get a software update. So I turned it on to do them while I would be out for a few hours running errands.
Turns out the FIRST thing is it transfers your eSIM. Then starts software updates.
So no working phone for several hours while trying to do errands.
@siracusa MacBook Air just spent 3 hours chewing on update. Rebooted. And is still running 15.7 after reboot.
Software update shows no updates for me now.