After my unhappy experience with 10.12.0 I waited 'til now to try again, and...
One of my three apps that broke is working again...skushed bug I believe, and the other two are replaceable, albeit with less elegant solutions.
My two major issues remain issues, though:
- Sierra takes 40 (yep, forty
) seconds to shut down, which is a reeeal drag after El Cap's fastest ever ~5 second shutdowns! 
- My trackpad has become stiffer...extremely annoying.
Note that during my 40 second shut-downs my screen is black and I don't see the usual spinning work wheel, AND verbose mode doesn't display
anything, although it works fine when I boot. (Feedback sent to Apple)
I'm gonna stick with Sierra anyhow. I'll live with the annoyances in favor of falling behind again, not that I'm experiencing any major changes. (It would really make me happy if SystemUIServer would remember the positions into which I move my menulets
every time I start/restart.)
The best part of the upgrade process was d/l'ing the installer with my new 50/50 Fios.
(I reverted from 100/100 after a month, because it was $10/month of overkill.)
Edit: Hmmm... The stiffer trackpad
maaay actually be a plus. More to come.
Edit 2: I couldn't figure out why a 3-finger tap wouldn't call up dictionary definitions, and when I launched Dictionary.app to see what was up I learned that I first had to d/l the dictionaries.
