Turbavykas has a point. An airliner's wing (and wing rigging angle) is optimised for one angle of attack. But having reflex flaps means that the wing can be rigged for minimum drag and the aircraft can be operated more efficiently over a wider speed range. After all, the required gubbins is already installed. Yes a mod. will have to be done for existing aircraft but that doesn't stop this feature being installed in new aircraft. Then, LRC might be slower but high speed cruise will certainly be more efficient - and let's face it, we often cruise in excess of LRC.