I'm sure they work pretty good and get some good ripples in the water, but it looks to me like it is pretty similar to a Wonderduck decoy. We have a Wonderduck hen in our hole and it scoots around pretty good and costs quite a bit less too. Also, the motor that runs the wings is inside the decoy as opposed to on the decoy's back like on the Mallard Master and I truly believe that Mojo and other motion decoy-wary ducks can pick that kind of stuff out. Here's a link to the Wonderduck, and no, I don't work for them.

http://www.wonderduck.com/