There are a few other options for doing that -- the two that come to mind: if both hands are on the keyboard, the standard Command-Tab combined with the down arrow key allow you to cycle through both apps and windows of a single app. Better though, a simple three-finger swipe up on the trackpad show all windows as thumbnails for easily getting to the window you want from any app. I use the latter constantly, saves time if you have a lot of open windows as you don't have to cycle among them all to get the one you need.