The advantage of flaperons is it simplifies building and linkage installation. The disadvantage is it degrades the function of both the flaps and ailerons. Separate flaps require two more servos and associated wiring.

They were, and are, used on competition fun fly planes. When the plane is straight and level, they are deployed as flaps which really tightens up a loop. When making a quick dash back to the runway at the end of the maneuver, they are raised as spoilers, literally sucking the plane back to earth and saving a few precious seconds on the clock.

Flaps are commonly used on scale planes to increase lift for takeoff and landing. They allow the plane to fly slower before stalling. They are also used extensively on control line planes.