I would say overall, I like it quite a bit.  It's fast, fluid, and, for the most part, just works.

What's great:

(1) Flip & Flip3D - w00t!
(2) Glass - damn pretty
(3) Search - yep, and the indexer doesn't spike the cpu any more!
(4) App scaling - fixed!
(5) Media Center - way faster and way more usable.

That said, it isn't all roses:

(1) When I leave my Dell 5150 alone for a day or so, i return to a "Display Driver Stopped Working" balloon in the task tray.  Now, I'd be fine with blaming NVIDIA for this, but if i click the X to close the bubble it keeps coming back.  I've tried rapid clicking 100x and it keeps coming back. Is this really the best way to alert me to a problem?

(2) When I'm playing music in Media Center the damn thing keeps throwing up the screen saver.  How hard can it be to shut the screen saver off while I'm in Media Center?!  Apparently, since this NEVER worked in xp, quite hard.

(3) Sleep has never worked.  I leave the machine alone and come back to the CPU spiking both cores in the morning.  I'm prepared, right now, to blame NVIDIA, but if it doesn't get fixed soon blame could shift.

What do you guys think?