This lens is an absolut must for any Nikon photographer. It's sharp as hell, it's ok cheap and the DOF is really outstanding. This lens purpose best with portraits and food photography. It's also completely ideal for low-light situations. If you can't afford the 85mm 1.8, this is the way to go.
Fast; Razor sharp (specially at f/4); Amazing DOF; Lightweight and Compact (can be fitted into a pocket); Price; A MUST for any Nikon photographer
Slightly soft contrast at f/1.4 but not really noticeable; Could be bigger in size, but whatever..