I generally don't have a problem with the finder, it does most of what I want plenty fast. My only real issue is that sometimes it wants to render a preview while I want to navigate through items/folders. If the preview could just be a relegated, subservient thread, (which didn't hold the file "open" while previewing it) then I'd have no real wishes left for the finder. It would be as fast as I am. Until then, I can still, and often do, whip through directory structures using keyboard strokes faster than X renders contents in a directory.
C'mon now, I hit Option-Apple-H, tab, d o tab, c o tab, I should be in my home directory, documents, code_homebrew, not home directory, documents, AppleWorks User Data ... there's no reason for my dual G4 to not keep up with that.
But you other guys, what's your specific beef with the finder? Window resize? Genie effect? What?