SHARP! Sharp on my test chart at all focal lengths at center and upper and lower right. Top left is also sharp with a slight loss of sharpness (VERY SLIGHT) at Bottom left. I tried re-seating the lens and made no difference. I use a tape measure and a laser level to ensure proper camera to chart arrangement. Tested with D800 and D750 body shooting same shots.
Bokeh is so-so. Build quality is cheap plastic everything, including the the mount. G gelded lens with no aperature ring. Low light auto-focus errors, but focus easily corrected with manual ring.
Despite the weaknesses, I like the lens. I keep it in one of my camera bags as a goto all-around use lens when I am on the go.