My club is here and so far all I have time for is a few swings in the back yard, it seams to take some amount of effort to make good contact with the ball in short grass. I will go to the driving range tomorrow and try it from the mats and see how it works.
But so far I can say it does have a use at least it will make you swing down with your hands in front of the ball to make good contact. Also my divots were after the ball.