This seems to be very interesting lens indeed. How come this lens is superior to 35mm from Canon, Nikon, Sony, and Zeiss ??
".......Let's start with the optics. It's remarkably sharp, even wide open, outperforming not only its Canon, Nikon and Sony equivalents, but also the far more expensive Carl Zeiss Distagon T* 1,4/35 in lab tests. Chromatic aberration is also impressively well controlled (both lateral and longitudinal), distortion is low and vignetting more-or-less typical for its class. The rendition of out-of-focus regions is generally quite attractive, although complex backgrounds can end up looking rather 'fussy'. The overall result, though, is a lens that delivers fine-looking images with the minimum of fuss, shot after shot....."