Sadly, the infinity stop wasn't properly calibrated as they usually aren't in these Korean miracles. Live view was used to focus instead of relying to the distance scale. At f1.4, less than half a millimetre of focusing ring movement is enough to ruin the sharpness of the image.
It's a big lens, but so is the camera (Nikon D800) I'm using too. I also tried the lens on a older film camera (Nikon FM or somesuch) and the lens honestly felt just too big for that body. I couldn't get proper grip of the camera and the focusing was a pain in the shooting hand because of that.
The bokeh is tad nervous and the bokeh balls show some kind of inner structure, which is from the aspherical elements I'd guess. However, that's usually not an issue if shooting stars and skies with this lens.
Stars stay almost pin sharp even at the very border of the image, this is remarkable feat for such a cheap lens. For example Nikon's own 24mm f1.4 suffers from bad case of astigmatism and chromatic aberrations.
Build quality is very decent, but the provided lens hood feels like its plastic is cut from a cheap bucket. It's thin and feels somehow finicky when putting it on the lens.