This lens has the sharpness to match the NX200. The bokeh is in the same league as the Pentax SMCA 50mm f1.7.
The mount is metal. The lens is focus-by-wire, so it does not stop at minimum focus or at infinity, but focus ring travel is slow enough to provide easy and accurate manual focus.
The lens is exceedingly light and small. The NX200 with this lens can be considered truly compact.
Distortion and colour fringing are not obtrusive. I shoot RAW.
Vignetting is noticeable at f/2. A hood is recommended if the sun is close to being in the picture.