I was looking into them too until I read the reviews from Cabelas on the product
http://www.cabelas.com/cabelas/en/templates/product/reviews.jsp?productid=490189

Sounds like there is a lot of flight problems, which means as RB stated the arrow needs to be properly tuned to the bow. I may still try it out, but sounds like I may have to get "special arrows" tuned just right for these broadheads. I think a lot of us watch the video on the gillotine website and think "wow...lopped his head right off" then want to try 'em out for ourselves. Funny how sales ads can do that sort of thing