I\'ve been testing mine out a bit at home doing a few comparisons on my new D700. It seems very usable at all focal lengths and f/stops, with the corners coming in better at f/5.6, and better still at f/8.
I don\'t have anything conclusive, but it seems to me to be sharper on the wide end than it is at 35mm. In particular, my 35/2 (a very sharp copy) seems sharper than the 16-35, especially in the corners, at the same f/stops. Might just be field curvature or some other quirk, though -- and I wouldn\'t be surprised if the 16-35 is better in terms of flare and CA.
It seems that it\'s sweet spot may be from around 18mm to 28mm, where it\'s pretty tough to beat (I\'ve never shot the 14-24, though).
