While we're on the subject of rating some of these popular lenses, I am quite impressed with the 24 f1.4 G, 35 f1.4 G and 85 1.4G although I have to say now that I had a brief chance to shoot the new 85 f1.8G on the D800...in some ways I almost prefer it to the 1.4G. The Zeiss 21mm is an absolute gem and a while back I tested it against a excellent sample of the Nikon 14-24mm f2.8 set at 21mm. Color response of both lenses were entirely different but resolution (sharpness) across the frame was quite close. I'd almost give the edge to the Zeiss. Unfortunately at the time, I didn't really test specifcially for distortion.
I've also used/tested the Zeiss 18mm, another fine lens from Zeiss although performance wise, it was somewhat behind the Zeiss 21mm. Regarding the Zeiss 100mm, I put it up there along with the 21mm although I don't yet have a handle regarding potential CA issues with its use on the D800.
Lastly I am not so enamered with the Nikon 50mm f1.4G. A very good lens but color response as mentioned is not to my taste nor is the OOF areas particulary attractive when shot at or near wide open.
Dave (D&A)