I dont' have one on my bow, nor have I shot one, but I have held and drawn bows with the grip on them and I have to admit they're pretty nice. The concept is very unique and definitely works. They have laser pointers mounted on the front of the bows that you can point at a wall and when you're at full draw you can torque your wrist all over the place and the laser stays put. My only complaint is that the grip is a little fatter than I normally like.

I could probably get ahold of one and mount it on my bow if everyone wants to know what I think. I'll be your guinea pig, so to speak.