Actually for guys looking to buy a good walkabout lens for a crop sensor body, but are not keen on getting the 17-55 due to
i) Possibility of upgrading to full frame in the future
ii) Lack of a Red Ring
iii) Lack of weather sealing and poorer built quality
can consider getting the 16-35 II. It actually translates to quite a useful 25-56mm range on a crop sensor body... with a f2.8 maximum aperture. If one day you decide to get a full frame or 1.3x crop sensor body, the 16-35 will double up as an awesome UWA lens.