SPD SL Pedal Information

yesterday i noticed a difference between the three SPD SL Models which is worth to be mentioned because a never did not read about this before. its said that SPD SL has the advantage of a lower distance between shoe and pedalbody, in compare to Look, a lower cleat. But thats only half the truth. it applys specifically to the SDP SL Dura Ace model, as only there the face is lowered. the follwing image shows this, notice
the level of the pedal in compare to the circumference of the axis, this is ca. 2 mm i think.


now beginning with the ultegra model, the contact point between cleat and pedal is not lowered:


Another reason for the dura ace model about 40 grams less weight.