I have been in both the 5.5 Uni Class as well as the F 17 class. We agreed in the 5.5 Uni Class to alow the F 17 rudders. Although I don't really think you need to do this upgrade. The difference is you eliminate the weather helm when converting to the F 17 rudder system. The down side is you might have a tendancy to stall more often when tacking. But its really a personal preference type of thing. Save the $ and leave it as is.