Focusing one half-tiled window now hides any non-half-tiled windows by raising both itself and the half-tiled window next to it.  

Example: The user has a half-tiled text editor (left), a half-tiled web browser (right) for documentation, and a terminal that isn't half tiled.  The terminal is focused and above the web browser.  Switching focus to the *text editor* now hides the terminal behind the *web browser*.

This behavior feels unexpected and counter-intuitive.  It is surprising to alt-tab or click on a window and have some other window spring to the foreground as well.  It's especially surprising when picking a window from the overlay.