Visually, I'm actually liking it.
As I'm getting an 11" MBA as my next and only computer, the iOS flirting is in fact something I want (both the visual cues and the new multi touch functions), due to the smaller screen and the portability of that setup.
For desktops I can't really say. Though, I'm currently using an aging MBP with an external keyboard and a magic mouse and the 2 finger swipe (mouse) for full screen space switching feels great. As does 1 finger swipe (mouse) for back/forward in Safari.
Actually, I wouldn't if applications could make use of several full screen spaces at once. For example audio apps such as
Record/Reason could have a full screen mixer, next to a full screen rack and a full screen sequencer. Or perhaps, if each full screen space could contain full screen "pages", switched between similarly to Safari's back/forward gestures.
Both Mission Control and Launchpad are growing on me. Only weird thing is that the dock is no longer of much use. Design/function wise it has become an indicator of currently running apps in my case.
Safari has a few bugs for me, such as disappearing close buttons (x) on tabs (pick a different tab and go back to the original and it returns).
The Dock sometimes get stuck mid-animation.
All in all, currently a few beach balls in Safari and elsewhere but on the whole it at least feels better than SL.
Almost lost my only internet connection after upgrading though, as I depend on a JAVA app for conneting wirelessly, and the JAVA framework is no longer pre-installed with Lion. Managed to find some poor guys open wifi spot, downloaded JAVA and got it all running in the end.