Have the 24-105. It is a favourite of mine. Find it very well suited to outdoor shooting which has been the bulk of my shooting to date. Having said that, I am seriously considering switching to the new 24-70 for the wider aperture. Am starting to do more indoor shots lately and am finding that I can have issues with subject motion blurring shots or high ISO noise issues. The extra stop should make the difference for me, barely, and the extra background blurring capabiity will just be a bonus. Just waiting to see reviews on the new 24-70 before deciding on it or a couple of primes instead.