Thanks, Steven. I really do like the lens. I had a problem with the autofocus, but it was fixed quickly by Sigma - very helpful people. In terms of waiting for a lens this size, I resolved the problem of cost by finding one on Kijiji. The only problem with buying second hand is that the 10-year warranty isn't transferrable, but as I said, Sigma was very helpful and its working perfectly mow. Certainly makes a huge difference in the quality of my animal shots.