I use my 24-70 for about two years, first at the D7000, currently on the D800. AF speed, processing etc. are very good and already dealt with exhaustively. If I'm honest, I find it difficult to assess the lens with a number of stars, because it absolutely has two faces for me. On the one hand there is the exceptionally good quality at medium and long focal lengths, which makes the lens for eg panorama shootings almost perfect. I have both the widely acclaimed Sigma 35mm 1.4 A and the Nikon 50mm 1.8G and both lenses are simply from f2.8 to f11 is not better when it comes to image quality. Only if extreme light intensity / Bokeh is asked these lenses come at all in the bag. On the other hand, the almost frustrating poor picture quality 24 to 27, in the border areas under severe field curvature (Engl. Field curvature) suffer. This is only a problem for those who want the sharpness from edge to edge, but for architecture and scenery is absolutely desirable. Here is the picture quality within the innermost 1/9 (when the image horizontally and vertically into thirds each) so super sharp as otherwise usual, but the greater part of the picture is just not really sharp, even at f11. Here, for example, was my predecessor lens that 16-85, the DX much better. This problem is well documented by relevant sides, although it hardly finds here in the reviews mention. Furthermore, here also interfere with the massive CA that can even remove LR limited. This demonstrates, unfortunately, but that the lens comes from the 12-MP-era of D3. There, the blur was still acceptable, but at the D800 the lack of sharpness is simply not up to date. Perhaps Nikon wanted here simply too much and has a 24-70 made an almost perfect 28-70 large (for me) flaws, perhaps you could have offset the qualities on the focal length range better. So I am often faced with the question of whether any but the Tamron was worth a try, even if there is not anything is certainly bright. I currently keep the lens and the focal range round down to the 18-35 from, but I think that you should be aware of as a potential buyer of this weakness to avoid disappointment.
