Dav0012 i understand your worries, i had an FL70 in mine and not only did i feel it was lacking in performance i couldn't get it to idle or respond to the throttle application properly even with some very experienced guys at the field giving it the once over, finally lost interest and bit the bullet and put an FS70 surpass II on it and after a few tries found a 12X7 master airscrew to be the best combo, i wasn't interested in 3d just good scale aerobatics and this combo delivered, unlimited vertical straight from take off and any other maneuver i asked it to do, couldn't be happier. I personally wouldn't go for a longer prop purely because i find the gear on the -46R very bendy and i can imagine grinding down a few props on a windy day.