You can not give this lens a "bad" criticism ..
You know what you are buying stop. The shoot absolutely superb, great image quality and bokehn is not bad either. Turns every picture of this, AF is cruel fast and accurate .. A given lens for us amateurs I feel very happy :-D
Great, great quality but bet on ICE!
Amazing good telephoto zoom lens
Really, really good lens. My first L lens and the first with USM. Awesome built and fast and accurate autofocus. The sharpness is as good as everyone says, really sharp.
Becomes incredibly beautiful portraits with sharp focus on the subject and blurred backround.
Less would be that it has no image stabilization for darker environments with slower shutter speeds, but it is affordable when it IS costing twice as much. If you can stay outdoors is a plus.
Awesome value, awesome lens. Buy.