One strange behavior is that in Finder (in list view for instance), page up and page down (or Fn-Down, Fn-Up) move the view up and down, but the selected item remains unchanged so that hitting the arrow keys returns the view back to the selected item. In order to select a different item, I either use the mouse/trackpad, hold down the arrow key to my desired item, or press Option+Up/Down to move the selection to the beginning or end of the list of files. I don't know of a way to move the cursor by one page view.

It's a behavior that I can get used to, but what I find inconsistent is that the behavior is different in iTunes. It seems like in iTunes, the only way to move the selection is either arrow keys or the mouse. Option+Up/Down doesn't do what it does in Finder.