I'm afraid I haven't got the best version of this lens, as the lens is a little softer than I'd want, and the color saturation is a little lacking. However, the softness is weak enough not to show up in a normal print, and the saturation is eassily fixed in photoshop as all the color data is properly there, just not quite popping. Decided not to try to get another copy out of fear of getting a worse version.
Noticed one strange thing color wise, seems to be blocking yellows a little bit as I have to add yellow and remove a little cyan to most pictures with this lens.
Build is extremly solid, altough cosmetically the EX paint job is peeling on the inferior portion of the zoom grip.
Focuses fast! I mean really fast, in poor light too. In fact, the damn thing so so excited to focus is yanks my hand a few cm's once in a while. It also has the tendency to focus not where I want it it to, but the focus is so fast I can refocus it as I want it almost instantly and still get the shot.
But of course, for the price, I still dont think you can get anything better.