I went to a dojo one time that had one. They called it "bullet man" because of the shape of the head. However I think it is essentially the same as what you are talking about.
We didn't use it for a class, rather a few of us broke it out after class.
Some of the most fun I have ever had
You can do anything, and I do mean anything to someone in that suit.
Full force groin, sternum, temple, grabs, throws. WOW
I didn't realize they were that expensive
Might be too much for the everyday dojo. But if you do alot of SD classes, and let regular classes mess about with it, It might pay for itself very quickly.
That would be a real "value added" component to any SD class and could be marketed as such.
If you can, Get one!