Generally speaking, the f/1.4 is the better lens in all aspects, price:performance included. Yes, it has another half stop available, but I don't shoot mine wide open. There are some sharpness issues when it's wide open (and from what I understand, on the f/1.8 as well). The 50mm f/1.4 really shines after about f/2.0 in terms of sharpness and clarity. I would spend the extra $250 and get it.