The Nikon 14-24mm f/2.8 AF-S sets a new standard in ultra-ultra wide angle lenses. It is the best on the planet, and by a large margin. The 14-24mm is significantly sharper than any fixed or zoom ultrawide from Canon or Nikon, and that includes Canon and Nikon’s 14mm, 18mm and ultra-wide zoom lenses.
The 14-24mm does things no lens before has done. It is sharper wide-open at 14mm in the far corners than a fixed 14mm f/2.8 is stopped down at f/5.6! For sharpness, the 14-24mm is blazingly sharp and devoid of any coma or softness at every aperture, everywhere in the full film and FX Digital field.
Full review at Ken Rockwell