Conclusion: My first Nikkor 18mm was the (great) f3.5 AIS... i loved it, but wanted more speed... I eventually found one of these (2.8 AF-D) for sale from a buddy for $200, bought it and never looked back. This is the only 18mm f2.8 AF prime out there (right?), and it fills that void nicely.
Pros: Size, AF Speed, max ap. of 2.8, performance.
Cons: Cost (retail price), can be difficult to find used, the hood (HB-18) is extremely difficult to find.
Conclusion: This lens I use a lot. The reach on FF is very nice for indoor photography. But also outside it is very usable. This length is difficult to master. Everything at close is overly large. The premium of this lens is it's compactness and speed.
Pros: Light weight, very compact, fast, good IQ.
Cons: Rotation of grip at AF, no weather sealing, not so good hood.
Conclusion: The list price of this lens is crazy but you can get it used for far less and its worth it. I do see spherical aberration on my digital bodies which is corrected easily (one click) in Nikon Capture. Other than that, this lens is very sharp from f2.8 and gets perfect stopped down.
Conclusion: Nice second prime lens to have for general photography.
Pros: The lens is much improved from the early manual focus 18mm F/4 and 18mm F/3.5 versions. As a lens for the Nikon DSLR, it performs very effectively as a 27mm wide angle lens (35mm basis). Contrast and color is better than most zooms that cover this range. Sharp, with good glare control. Good at F/...
Cons: Lens hood does cause some light loss. I do not use it normally.