This is my first Image Stablized (IS) Lens, and unfortunately, a very slow one. Optically, this lens is very similar to the 28-105mm f3.5-4.5 lens I had, and it was a very good lens considering its low price. I am able to consistently get sharper pictures from this lens, but, at 135mm, the maximum aperture is f5.6, something I am not used to. The view finder is very dark at this aperture. Overall, I think it's a very good lens for every day use, especially for traveling. Pair this lens with the Canon 5D, you would have a reasonably wide end with mid telephoto reach. On a 1.6x crop camera, this lens is not quite wide enough.