Now that I've used it, my paranoia has passed a bit. I still don't like certain things, but I've learned to adapt.
The weird, in-between issue is Mission Control. It's really good at what it does, but it's not a valid substitute for Exposé, particularly when dealing with an app with multiple windows. I used to be able to press a function key and see full previews of every window so I can tell what's what. Now if I go into Mission Control, I have to see ALL my open apps and when I pick an app, it overlaps the windows. Uh, durr? on what planet is THAT an improvement?
Launchpad requires meddling about manually, but that's really keeping in tune with iOS, and you can still dock your Applications folder and use it just like in Snow Leopard, and never use Launchpad. That's fine.
The backwards scrolling is reversible, but I would suggest that Apple only enable backwards scrolling for its Magic Mouse and Magic Trackpad and leave my damned MX518 alone. It's not rocket surgery.
Otherwise, I think Finder is a vast improvement over SL - it remembers how I had a folder set (icons, list, etc.) and actually respects that, more or less. Performance is about like Snow Leopard - the days of "faster on the same hardware" are over; OS X is where it needs to be performance-wise, unless you're trying to play Starcraft II.