Everyone needs a wavefolder. It took me some time to properly grasp this module, but now it makes it's way into almost every patch I make. You can get a huge range of sounds! It's best fed with a triangle or sine as the wave folding circuit adds lots of harmonics to the signal. Adding some slow modulations to the "symmetry" and "harmonics" inputs can create an ever changing sound that never sounds the same twice!
A great tip I learned with this is to keep the input level down low, it is easy to overdrive, and by doing that you may miss the subtle morphing waveshapes that this module excels so well at.
A small issue I have with this is the depth, it's a little bit deeper than most modules so it may have trouble fitting in a shallow case. (No problem using any of Doepfer's excellent racks though!)
I don't think there is another wavefolder that sounds like this. One of Mr Doepfers most unique creations.