I jumped on the upgrade as soon as it was available - even before the midnight "release"
since I'm an impatient nerd. So far, I love it. A lot of the menus and animations feel very Materialish to me. It looks mostly great, and most everything is smooth and fluid. And I have a start menu again without resorting to any hacks.
I still have to figure out what's going on with my Bluetooth (or, more specifically, the magical way in which the computer refuses to see any Bluetooth devices), but that's the only lingering problem I have from the in-place forced upgrade.