I'll add my two cents... went right from stock Froyo, didn't data wipe or any of that good stuff (I may be nerdy, but I value my time, and setting up my phone all over again is never fun-time for me). Love the new build, screaming fast. Nice visual touches as others have noted, but of course many of you will turn up your nose and point out you've had 46 other GB leaks before now. For those of us who are experiencing it new, however, I like the look.
Only issue? The much-reported sync icon. Been fussing with sync options to try to make it go away, but no avail - sounds like the only real solution at this point is a wipe. Given my aforementioned aversion to said wipes, I'm more than happy to let that sucker sit up there for the time being.
Otherwise, the build runs great and I haven't seen any issues. Battery life seems on par with Froyo, but I haven't done any crazy testing to prove that - just anecdotal evidence.
Almost makes me feel like the ol' BB Storm days... every new OS that came out made it better and better. Except, that phone was a huge pile of crap that I simply dealt with, whereas this phone started awesome and just keeps getting more so. I'd say if Moto can fix that sync icon issue for upgrades, they should pull the trigger on this one. In fact, I'm now wondering if that particular issue isn't the reason why this build was pulled from OTA in the first place...