If you have not used flaparons before.... I strongly suggest that you Dont use them on a plane you really are fond of for the first time.... They are difficult to set up properly and add a higher degree of Stall tendency to most planes. The planes you mentioned, Vipers and aggresors have already have a higher degree of stall characteristics than many planes, for example Mavericks and Bandits..the planes you are referring to being ducted fans does not help you either especially if your engine loads up on final. I have flown flaparons a few years ago on a ducted fan aggressor. I personally dont like them because split flaps are so simple and predictable . Dont get me wrong, flaparons ARE effective, they just change the characteristics of the plane too much. ( for me at least )... Ray Blair