I am looking to replace my canon 17/85mm IS 'walkabout' lens and after trial shots taken with sigma 18-125, canon 28/135 and canon 24/105 F4 L IS (together with images using the 17/85)
am initially most impressed with the 24/105. All images taken @ F8, focused on the same point and at max focal length
This is an expensive lens but after magnifying @100%,cropping by a similar amount and sharpening in CS3 the quality holds up extremely well.
I have obviously only had the chance to carry out limited trials and would appreciate any advice from anyone who has made a similar move before I spend a load more cash !!!