> Also related, OSX menu items have a gap between them; clicking on that gap closes the menu (I think).
There isn't a gap between every menu item, but clicking on the horizontal dividers or disabled menu items does close the menu without doing anything. The way that Windows does it seems better, there it does nothing at all, not even closing the menu.
Good point - it's only on menu dividers that this occurs. It just so happens that some menus (e.g. the main "Chrome" one) have a divider for every other item, and the dividers are about 10 pixels tall. I much prefer the Windows approach, but I'm not sure even that makes as much sense as just selecting whichever item is closest.
There isn't a gap between every menu item, but clicking on the horizontal dividers or disabled menu items does close the menu without doing anything. The way that Windows does it seems better, there it does nothing at all, not even closing the menu.