Just bough this lens to go on the front of my Eos 400d. First thoughts are: It's awesome. Fast, Sharp and Bright. No distortion at either end of the focal range. Great value for money if compared to Nikon's offering which does not even have IS.
Talking of IS it's excellent allowing me to shoot hand-held down to a third of a second.
I am a keen 'all around' amateur photographer. I wanted a lens which could do both landscapes and portraits as well as travel photography. This lens is great. It's very sharp, and the fast aperature makes it good for low light photography eg weddings. The glass is of the pro 'l' quality, although the build is plastic, but even so it is a heavy lens. I would recommend it to anyone who wants something better than the 'kit' lens which might have come with their Canon.
I continue to be blown away from the pictures I get with this lens. IQ is truly superb, sharp wide open at all focal lenghts. And if you stop down a little, it is super-sharp everywhere, corner to corner, edge to edge. It's a great walkaround lens.