First, it should be mentioned that I first operated the lens on a D800. Convincing results achieved only in Live View mode, since the AF was completely inconsistent with Aperture 1.4, the joy was marred accordingly.
Have therefore also subjected to AF adjustment at the Nikon D800 Dusseldorf. After that I was able to photograph halfway fail with AF at different distances using the Sigma USB docks and to which different settings. Halfway because of different AF reacted with glaring sunshine and cloud cover or dusk. Curiously, my Nikon behaved 24 - 70 is not so at maximum aperture. Ergo -> Sigma is crap, the other power voices are right, the Objekitv is uncorrectable.
By a lucky chance I could get a cheap used D800E. After that, my perspective changed on professional Nikon fixed focal lengths, for Nikon requires extremely ambitious prices.
After buying the D800E I have the lens again corrected using the USB dock throughout with -11. Is not a little, but - except for the Nikon 24-70 - all Nikon lenses have to correct with AF fine adjustment in the camera. The focus is located 100% conditioned at all apertures and in almost all lighting conditions.
Compared to Nikon AFS I 24 1.4 - Nikon AFS 28 1.8 - Nikon AFS 85 1.4 taking into account the important aspects of ME. Resolution at full aperture (1.4 or 1.8 with the Nikon 28), chromatic aberration at maximum aperture and high-contrast edges. Optical power at the edge at all apertures (yes I am, among other things, a brick wall clippers :)). The Bokeh also played a role, although not as important as different focal lengths areas and different image effects. Of course, I also photographed photographically :) sexier designs.
The result: Sigma beats all lenses with respect to the above criteria. Offenblendig came the Nikon 24er closest in terms edge performance and chromatic aberration. With regard to the resolution '85 came the closest there was offenblendig also green and purple tinged -> slight chromatic aberration. The edges of the image were dimmed almost as good as at Sigma. The 28er was offenblendig for chromatic aberrations cruel, I could see "purple rivers" at edges contrast. In far closed aperture (8) it was pretty good to keep up with regard to resolution and edge performance, however.
My personal conclusion: The lens is the answer to the question why I shoot camera with a high resolution full frame and several kilograms of drag through the area for me for the most part. Incidentally, I am an avid Fuji X (X-E1) APS-C clippers. In this performance, the ~ 725 (lens) + ~ 50 (USB Dock) over priced. Sigma is with this objective and from my personal point of view of the company Nikon - pardon the expression - the bare ass. Definitely a lens with the WOW effect.
PS I can not rule out that the tested by me Nikon lenses were all Monday models :). Hope not verbally Nikon fans ('m also a fan of 2,8er zoom;)) to be stoned.
