I like to have multiple virtual desktops. I put my e-mail application on one desktop and my development environment on the other. This way I can keep my window list for one desktop minimal. Otherwise I have to use
Alt-TAB all the time to get to the correct window. With VirtuaWin I can have multiple desktops and switch to them with simple shortcuts, like
Win+1 for desktop 1. Or
Win+right arrow to get to the next desktop. VirtuaWin is very fast on my machine and therefore very useful.