For the most part everything is pretty rad. Full-screen apps are a welcome addition, and Mission Control is the best thing they've implemented in their OS in years, even if its just a beefed up exposé.
It's not without faults though. Only native apps support fullscreen, and I still use Chrome because Safari just dies on me after a couple hours of use. The new gestures are altogether worthless and unnecessary, and the "natural" scroll change is fucking stupid and makes no sense on a laptop where you interact with a middleman device, not the screen itself.
I'm running it on an early 2008 macbook pro with only 2 gigs of ram so the OS lags quite a bit now, but its to be expected. I'm thinking about buying one of those new Mac Mini's and connecting it to my HDTV to use as my desktop computer, and then just a netbook/tablet for my portable needs. I won't end up spending too much if I go that route, both together only a smidge above a grand.