I have both the Fear Factor and the X Factor Deuce. My Deuce is shined up and the Fear Factor is dull. The Fear Factor starts much earlier and the backend is more mellow, but continuous. The Deuce goes much farther down the lane with more of a snap in the backend. I have found the Fear Factor does not work well for me if I try to come around the ball and swing it. For me, the best results are going more up the back with an end over end roll. The Fear Factor wants to go into an early roll so let it. Don't bring the Fear Factor out unless there is oil in the heads. The Deuce seems more receptive to different releases. Also it gets through the heads much better.