I know the low light capability is good and all, I have the 50 1.8. But all in all, the speed difference between the 1.8 and 1.4 isnt a WHOLE lot. I know with the canon 1.4 its just simply built a hell of a lot better than the 1.8 so I can see where its better overall and worth the price difference. The Nikon 1.4 really isnt built a whole lot differently and is nearly identical, it just comes down to the bokeh factor I think, being more "natural" as has been mentioned.