I do not have any of the Zeiss lenses for Nikon, but I have two of the Zeiss ZM lenses for Leica M. They're incredibly sharp lenses that fully equal Leica. I have a Leica 50mm Summicron too. The only downside to the ZM lenses is build quality, which is not up to Leica standards. Current Nikon lenses are plastic garbage, so the Zeiss lenses will exceed them in build quality by a long shot.