I was able to get a friend to pick one of these up for me in Japan and I am glad he did. I have the Sigma 10-20 and it's a great lens but sometimes for interiors I'd like a faster lens. I had the nikon 12-24 in the past and got rid of it because I felt and indeed still do feel the Sigma is a better bet.
This lens is plenty sharp enough at 2.8 across the field of view and just gets sharper as you stop down until you hit diffraction.
The zoom ring is well weighted and the manual focus ring has enough travel. I like the push pull to swap from manual to AF but would prefer the full time override given by an AFS or HSM lens.
For the D3 I have the 14-24 and it's everything that it is cracked up to be, but for a DX camera this is the best out there at the moment and the 2.8 is icing on the cake.