First thing it did was copy my "Google profile" to the watch. First thing I did was go to APPS and DEBLOAT MY WATCH!!! WOOHOOOO!!!!!! No more Amazon or Ebay app!
New "quick settings" is so much better. Swipe down and everything is on one screen. Airplane mode, volume, settings, quick brightness... minor but big improvement.
Faces works a bit different. You can setup a "favorite gallery". Pick a few faces to go there and you can switch between them SUPAH FAST. Guessing this is so you could have like your day face, your after work workout face, and your night face all within a swipe away from changing. Yes, literally a swipe away. Have fun getting used to swiping left or right to change faces now.
App launcher is much improved. And configurable. No longer are they listed by what you use last. But now you can say "I want these 3 apps at the top of the list".
So far so good!