On MAC have the ability to have floating windows permanently over a docked window even when the docked window has focus. This is the behavior on Windows and it is great. Having to float all windows, resize and move them about while making sure they don't overlap is very inefficient and time consuming. Also using the windows/arrange commands are less then optimal since you are wasting screen real estate.I use this all the time on windows when I have a large design docked and floating over it I have smaller reference files or smart objects and I need to see both at the same time. When I move to a Mac it really disrupts my workflow as the non focused floating windows disappear.