Summary: This lens has surpassed my expectations. It is a very good light lens. The lens does not hunt to autofocus. It is fast enough on the telephoto end (f4 at 70 mm) that I use this lens as my general walkaround lens. This lens is good enough to use for professional work when you do not want to use the heavy pro zoom lens. It was one of the best ebay purchases of the past ten years for me.
Summary: Excellent for the price! As a casual photo hobbyist, this lens works well for me. I bought this to replace another Sigma lens and am very happy with the quality of the photos this one takes. Does not do macro-style shots very well, but is great for walking around. Good: Fast autofocus, light-weight and still feels sturdy, capable of crisp and clear photos, price Negative: No macro, a bit soft in natural light in-doors - took some playing with to compensate