I triangled-away (was already using a basic rooted stock), undid my root/reflashed to original stock using Odin, factory reset, and actually installed Kies on my system for this...
Yeah, I'm paranoid, want to be sure I can warranty return/replace if something goes wrong with the first big update to the phone (only had it a couple of weeks) before I go whole-hog.
Plus I figure it'll take a few days for people to figure how to root this one, and I didn't want to wait. I can live without root for a few days.
(This post hyperlinked to give people not as familiar with things starting points to do the same if desired)