Quite different this lens: The housing acts with value and good tack to use. With my D80 is fast, takes great images and allows great prospects. In the last sailing holiday, it has allowed me for the first time to make great pictures from the cockpit of the complete sail area. Of course, the mast is bent by the distorted representation ", but the results with deep blue sky and the star-shaped flare around the sun great effects.
In combination with a polarizing filter (necessarily to buy) can be landscapes represent great with cloud formations.
Even photographs of people in their working environment, I think it's great because you can map the person in the center, while at the edges much is captured by the environment, but that does not distract the perspective distortion of the person.
The lens is really fun!
Vignette is at the focal length probably inevitable, but is still in the frame and can be combined with most programs indeed rework when the time does come. Distortion is also normal at the focal length and makes so a part of the special stimulus from this focal length, but you have to practice, to heal the sick this effect.
I would buy the lens at any time.