My impression on the F-16 was that flaps aren´t needed to slow down the plane for landing.. it already drags out nicely by itself so the flaperons where set for giving extra lift but no drag at all. (15 degrees). The nicest, shortest and easiest landings where done this way.

About the difference on the slow speed behavior it seemed to me that the flaperons gave more solid roll control, regardless of using conventional elevators or tailerons. The choice of conventional elevator setup was made as it seemed to react better at higher speeds.