I bought mine in early 2007 to replace my Canon EF 28-105mm f/3.5-4.5 II USM. What a huge difference! I was between the Canon EF 24-70 f/2.8, the Canon EF 24-105 f/4, and the Canon EF 17-40 f/4 at that time; but finally went for the 24-70 since I needed a general purpose lens and preferred to have f/2.8. With this one lens I could shoot both landscape and portrait without changing lenses. My copy is very sharp, even at wide open. The color, the detail, the contrast and the saturation of the pictures from this lens are excellent. The 24-70 lens focuses very fast, quite, and accurately even in dim light. For portrait, this lens is very capable of making the subject stand out due to its pleasing bokeh. Highly recommended.