Yesterday I shot a direct comparison of the Zeiss ZF.2 25mm f/2 Distagon against the Nikon 24mm f/1.4G. This will be posted in my Zeiss Guide soon. The scene below offer a wealth of fine detail for seeing just how these two lenses compare.
I used the 24MP Nikon D3x, but given the impressive results, I do wish that the Nikon D800 / D800E were already available. The D800E is going to be a lot of fun going forward methinks.