I guess it all depends on what you like. Do you need flaperons on a Cub? I would agree with "no" for that answer.

On the other hand, a buddy of mine had a lot of fun with flaperons on an LT-40. He mixed rudder to aileron on his transmitter to get around the turning problem. He also mixed in the needed amount of down elevator to keep it from pitching up. It was fun to see him at full speed on the step and then hit the flap switch and watch it leap from the water like it was on a high speed elevator. Of course, this is definitely not a scale move.