I have an Ai f/2 and a long-nose f/1.8. If you want to pixel peep, of my samples, the 1.8 has it by a very small margin wide open (this would be a 64" wide print so, what's the point...). I prefer the f/2 because it does this thing wide open that I like. In fact the f/2 Ai is so sweet and so cheap I'd buy one even if I didn't have a Nikon, sort of like some people did with Windows 95 because, you know, you'll need it eventually.

s-a