They are really great, I have two screens, a mechanical keyboard and a good mouse. When I press they key with the laptop up, I suddenly have 3 screens to work with. If I run any long running process or zi want to listen to music instead of running anything on the laptop I just press the switch and the top screens connect to the desktop while I can keep the screens showing me the progress of those processes below (the screen of the laptop itself).
Peiole talk about working with 2 screens, but I quite enjoy using 3 haha.