10 out of 10 points and recommendedRange, low distortion, good color saturation and contrast. Well constructed. Fast and accurate focus. Acepts filters.No weather sealing.
The build quality is very good. Image quality (sharpnes, colors, contrast) is very good at all settings.reviewed April 2nd, 2013 (purchased for $850)
AF is fast, quiet and very accurate.
Sharpness in the center and borders is very good, at the extreme edges is a bit soft under 12mm wide open.
Near 20mm the edges are good again, and the lens can be used wide open without problems.
I catch very nice pictures. Use it is very very fun.