Played with it for a while.. unable to see how it would improve productivity. Was unable to get previews in Window Switcher mode. Not all windows were previewed in Dock for Chrome and some other apps. Some apps with a tabbed system like QSpace were shown as a single window. DockDoor had a hard time creating previews for some apps unless they were in the forefront, and even so that at times would not update preview to the real opened windows.. or not preview at all, or only show me a few when I had many more opened as in my Browsers. Seems to not play well with FullScreen and Show/Hide dock. Dunno, I guess it flies over my head and takes quite a bit of customization to benefit from it. If such an app takes me too long to wrap my head around I delete it. I've never seen such an app (Dock and Spaces enhancements) really come of its own over the years, they come and go. I won't grade it, maybe given the time it could be useful. Not for me.