i use both the nikkors and sonnars on a regular basis. i on't use the "b" word, but the plasticity of the sonnar is noticeably better on most examples in my opinion. much better for standoff portrait work. having said that, the contrast performance of the nikkor is better and seems to have (probably as a result of the increased contrast) better resolution of fine detail. i use it for landscape, especially off a tripod where you see the small differences most easily. hope that helps!