I tried it a while back, and it didn’t click with me either, though I liked being able to switch to specific windows inside apps.
Years ago I bought Witch, which does similar things, but I ultimately reverted to the OS default as well. (But I’m a big fanboy of Witch’s developer ManyTricks.com: I use Moom a dozen times a day and and their DeskTop Curtain often when I’m doing screenshots.)
Command Tab Pro increased my productivity by a lot. I have always a lot of open windows (especially Word documents) and I can switch between them very quickly. I almost don’t need a second monitor anymore 
All the information is at mi disposal almost immediately.
I can see the value of Windows Switching which uses Alt Tab to run through a menu of all the open windows. How does the Command W and E work for you to flip between windows? I’m too use to Cmd and ~ to change the memory muscle.
I do not really use windows cycling that much, but when I do, I am using “~” as well But the alt+tab is great for mutliple Word documents since I can navigate them based on their name and do not need to look on the opened window if its the right document.
Now that I had a look at it, it seems to me that the main feature of Command Tab Pro is the numbered shortcuts, right? I don’t think this brings too much advantage for me personally. I have to figure out which number the desired app has right now and then use another finger to press that number key. In this time I can tab often enough to get to the app anyway. Or, if sometimes it’s really at the end of the list, I can still use the mouse.
But I see that it can be of use for people that work with a lot of app, especially if they have specific “worksspaces” on different screens.