The 24-70 will shoot sharp images at f2.8 and the 24-85 will need to be stopped down a little to get the same results. If you care about size, weight and cost get the 24-85. If you want the best zoom lens in that focal length range, and don't mind the extra cost or weight get the 24-70 f2.8. If VR is important to you get the 24-85, not much else to say. I would go to your local camera store and shoot few frames with each lens using your camera and card to get the feel of each lens. Then go home and compare the results on your computer, the rest should be easy.