Absolutely beautiful and solid lens. Heavy, as you would expect, and obviously with the magnification any sort of movement is magnified, but if you're careful you can use it without a monopod/tripod if you brace your hand/arm, or if you're in bright light so that you get a very fast shutter speed. I've wanted a longer zoom lens for years, and finding this at such a good price was brilliant as long zoom lenses have always seemed out of my reach. I've used Canon and Sigma lenses and have to say that I prefer the Sigma: they are less bulky than their Canon counterparts, and the optics are very good indeed -- in many cases better than the Canon. The construction is very solid: when you point the lens at the ground the weight will make the bigger ones slither open slowly; if you do the same with even a Canon 200mm zoom it will slam open. So if you're looking for a really nice zoom lens, you would be very happy with this one.