Got the machine back yesterday. It took nearly 13 hours to restore my data from the Time Machine backup. I'm slowly getting apps up and running. Oddly, Traktor didn't want to re-registers. Less fortunately, Nord VPN doesn't work at ALL now. The client flat out refuses to log in. I'm going to investigate that further tonight.
Weirdly, I spent longer in the Apple Store picking up my laptop than I spent dropping it off. I did have some time to peruse the peripherals they sold. The thing that impressed me most was this thing:
CalDigit TS2 Plus. It's over $300 on AMZN, but only $250 in the Apple Store. It powers the laptop and provides a really thorough hub, via one connector. I don't even have a USBC equipped machine, and I kind of want one.