Update: 10 is generally running pretty well. Battery life is less good than it was, but not horrible (I was getting exceptional battery before). A few apps which haven't updated get laggy, but other than that, no known problems so far.
+
I really prefer the horizontal carousel for recent apps!
The new "zoom" feature is better than the old one, as it's now full screen/window.
Home screen fonts are slightly bigger and contrast seems clearer
-
Camera controls are laid out completely differently with different icons. Took me forever to realize lens selection had moved to the bottom of the window (and the icons have changed)
Battery isn't quite as good,especially screen-on time
Overall, a decent update. I'm mostly relieved this one didn't toast my phone!!!