I've had two 24-105's, bought one used, sold it when I bought a new copy with the 5DII kit. Good wide open, better stopped down. I bought the 24-70/2.8 II, and much prefer it. Ended up selling the 24-105 for lack of use. The 24-70 II IS sharper and has less distortion at the wide end. I do have fast primes, but having an f/2.8 walkaround lens is useful, to me more so than the extra 35mm of tele.