I rented this lens and some 35mm focal length lenses for use on my D800E, for landscapes. I found it inferior to the Zeiss 35mm f/2 and the f/1.4 in sharpness outside the central area. And inferior in color and contrast. I tried the Nikon 35/1.4G and it was great in the center but inferior in sharpness outside the central region and much worse than the Zeiss lenses. The 40mm ultron may have been a bit better. The Nikon could have been a bad sample, and for that matter the Ultron as well. The Nikon 35mm/f2 autofocus lens is a dog unless stopped down to at least f/8. BTW the Zeiss 1.4 is not that sharp/contrasty in the conventional sense until stopped down to f/5.6 or so.
To put things in perspective having just one sample of each lens is somewhat of an iffy proposition. And, my assessment was done pixel peeping at 100% on a monitor. I didn't do test prints.
I ended up purchasing the Zeiss 35mm/f2. Bokeh is not quite as nice as the Zeiss 1.4 but I found it better in uniform sharpness at the wider f-stops, much lighter, and cheaper in price. That being said I'm downsizing to mirror-less and my DSLR equipment is almost all gonzo now.
"What the World Needs Now", besides love, per the famous song, are smaller lenses that are of the highest quality - fit to make full use of the high megapixel cameras. Why the h_ll Nikon hasn't come out with an updated 35mm/2 autofocus lens that would fit the bill is beyond me. Surely a lens with xlnt bokeh, high sharpness across the field w/o having to stop down to f/8, state-of-the art design and coatings, is beyond me. Is the difference in bokeh and background blur between f/1.4 and f/2 so great that it warrants huge heavy very expensive lenses? Apparently so, since so many people buy them. Now I hear Zeiss is coming out with high performance lenses in 2013. However it doesn't seem like a 35mm is among them. I wonder how heavy and huge and expensive they'll be.
My recommendation would be to rent some lenses and try for yourself (I rented from lensrentals). A lot of this is personal preference and the small size of the Ultron and basic decent performance and price might outweigh pixel peeping differences.