Oh man where to begin...
New startup/shutdown screen
12 new sound schemes
many new wallpapers and account pictures
gadgets no longer need UAC turned on
It's gotten quite a bit faster since build 7000
some new icons
smoother animations (mostly on lesser hardware)
newer builds of built in programs
less drivers need to be installed
aero peek is more used
jumplists cleaner with a set amount of maximum items displayed
download folder option in start menu
faster searches
I find some applications (like lightroom) work better
games runs a bit better (I was getting some tearing issues in some games in earlier builds, not anymore)
Little things here and there that have been tweaked
Should I set a restore point in case the update doesn't go well?
If you choose to update it then theres no harm. A clean install would be ideal, though not everyone has problems when they upgrade.