Summary: Nikon has made high quality lenses for a long time. The new ones include coatings and autofocus and stability control or vibration reduction. The old lenses don't have all those features, but they have one thing, high quality optics. I own a D800 and have been collecting some old Ai-s lenses and they do not disappoint. This is a nice lens. The pictures are wonderful. The old lenses are worth shopping for.
Summary: I needed something wider than my 50mm 1.8 for shooting landscapes and also interiors of houses. I picked up this 28mm lens and am blown away. The lens is very sharp!! Also, the build quality of these older Nikon D series lenses is great. To me, they are honestly better than the newer G versions that are all plastic. This is a metal bodied lens and it looks and feels great to use!
Summary: Prime lenses are great because of the wide aperture range. I actually use this lens as my default lens for my camera. Optical quality is also great as is build quality, made of metal and not plastic.