I received my copy today, and I must say that I am very impressed with this lens' sharpness wide open and the way it renders colors. I took a few quick shots of my wife, and I was blown away. I'll be testing the AF speed on my children tomorrow, but I was able to get shots I was very pleased with using an 85L II, which had very slow AF, so it shouldn't be a problem. At $500 I would highly recommend this lens.