4. In Bridge CS2, there's a handy keyboard shortcut to select your star-rated images, e.g., crtl-alt-1 if you wanted to see only your images with at least 1 star. I use it several times a day. In Bridge CS3, that function has been moved to a cumbersome Filter tab that takes multiple mouse clicks. The shortcut is gone.
My rule about sortware upgrades is confirmed yet again: whatever was easy now is harder. What used to take one step now takes three.