There are (at least) 3 versions of that lens, a push pull, a 2-ring and an AF-S. I owned the 2 ring for several years and used it frequently before I fell into a deal on the 70-200 2.8VRII. Focusing was OK, depending on what you're shooting and what focus method you use. The VRII lens focuses faster, but is 2x the price (new).