The higher your KE the better chance your going to have of getting full pass throughs on game. The larger the cutting surface of a given head the less chance you have of getting a full pass through. There comes a time that with to low a ke and or to large a cutting surface your going to hinder your success. For the rage heads I prefer 55 ft/lbs as a minimum. If your setup is less than that go with the Rocky Snyper broadheads. Very similar design but smaller cutting diameters. Here is a link to my reviews of the rage heads.
http://www.broadheadtests.com/NEWHEADS.html