I bought one about a month ago, mounted it, took a couple shots, but have not yet had the time to really sight it in. I think it will work very well. Peterson's Bowhunting reviewed it in their most recent issue and gave it very good marks.
It is suppose to be good for helping you to reduce torquing and maintain very good form. It is also supose to be much better than a peep during low light conditions as well.