Actually I want/need it to be very sharp in the corners. Most of my shots the focus point is more to the corners than to the center. Photography 101.How sharp do you really need a wide aperture lens to be around the edges? Most of the time the edges are blurred from being in the out of focus area anyway. Give me a good sharp lens on center and I am happy. The 14-140mm is the sharpest m4/3s lens I have encountered in that respect.