I'm a big fan of the up reflex myself.

I build scale. Scale planes will often have the hinges near the upper surface of the ailerons. The bevel will be asymmetrical and moslty below the hinge point. So simply aligning the bevel of the aileron with the center of the wing trailing edge won't work in this situation. In this situation, you check that no part of the airleron is sticking up above the wing or hanging down beneath it. So the alignment check is on the upper and lower surfaces.

It appears many folks don't check this when building. It is very common to see mis-aligned ailerons at the field. Mis-aligned ailerons will rob you of speed and effectiveness.