Does anyone have any experience with the Grip Inserts offered by Escapade Gaming ( http://escapadegaminggear.com/product/anti-slip-inserts )? I can't seem to find them in the U.S. and was hoping to get some feedback on them before deciding if it was worth trying to have them shipped to the U.S. Do they work well? Any problems with them or executing maneuvers acurately with them?