Viper is really nothing more then a fast trainer. It's light for it's wing area. if it's coming in too hot then it's nose heavy. You said you are flying from grass so roll out shouldn't be more then 20 ft. I am still curious where you plan to fly it. I know the flying sites around here pretty well and the only sites I know about that are grass are electric only. BTW Sheldons has a crap load of the APC Pylon and sport props in stock suitable for Q500.