It seems that some people have issues, where I have none whatsoever. But I'm quite a fan of clean systems (nothing APE for example and similar 'haxies'). I'm also the person that from the beginning of OS X tried to adapt to the way Apple wanted us to use OS X (instead of the OS 9 way of customising the system around the user), so I might be more 'default' than others.
For me, the past three or four days have been bliss, since everything worked and worked so fine. Exposé is something I have a hard time getting used to, but I like it and am slowly getting the hang of it.
One issue I'm having is that after some time, the Apple-Tab app switcher just doesn't come up again. Then I go on working for a while using the Dock to switch apps, before I logout and back in - which solves the problem. I guess the app-switcher is an app of its own that eventually dies without restarting, but I haven't found out what it's called (or perhaps it's not as expected, maybe a part of the Dock...?) so I can't launch it by hand.