I used an Apple TB4 cable to transfer ~500GB after charging both the source 16PM and the new 17PM to 100%, because I remember last year or the year before the phones would drain each other attempting to suck charge from the other. Seems Apple has fixed this, once the transfer starts, charging stops on both. I had both sat on an ice pack for cooling, which worked wonders. The first estimate it showed me when you select wired transfer said about 4.5 hours, but real time it took almost exactly two hours.
Honestly it was the best and fastest it’s ever been for me, because while even an encrypted Finder backup would preserve most data/settings, the phone would still have to sync my 200gb of locally-stored music after restoring the backup for 2 hours. The phone-to-phone moved all my music over without a subsequent Finder sync, saving those extra couple hours.
The only things that still needed post-transfer work were moving my cell plan over, apps downloading, and logging back in to banking apps. Even a handful of my Apple Pay cards automatically added without me entering the security codes. The Watch switchover happened without me even noticing.
Best setup ever.