The price is quite another matter. If you want to buy this lens separately you have to spend almost $1000 for it and it's a lot. Buying it in a set with the camera is a more sensible and preferable solution because then the surcharge is just about $600, a price point that can be called acceptable.
shapely and handy casing,, good image quality in the frame centre,, sensible image quality on the edge of the APS-C/DX sensor,, moderate longitudinal chromatic aberration,, sensible correction of lateral chromatic aberration,, low spherical aberration,, negligible vignetting on the APS-C/DX,, lack...
a lot of distortion problems on RAW files,, huge vignetting on full frame.