I've got multiple lenses of all the versions of the 180: P, P.C, ED and AF. All are fine lenses. I'd go first with the ED version, simply spectacular. The AF might be better closer up and the internal focus makes it a fast handling lens, but for the money the ED can't be beat. Amazing image quality: I just posted a shot done with one of mine at http://four-silver-atoms.com/2012/11...-nikkor-180mm/
However, the 180 and in particular the P.C is a real sleeper. Very sharp especially mid-distances, more color fringing closer in and further away wider open on digital but digital shows lots of this anyway on longer older lenses and software tweaks can handle it well. The P version had a reduced multi-coating, and after Pentax went nuts on promoting their Super Multicoating Nikon had to follow suit and offer lenses with additional multi-coating, and that became the P.C version. Both are fine, the C version handles backlit, flat light and strong colors better, but the P has a certain delicacy to B&W images, a lovely portrait lens for the ladies if you can use a lens that long. Both can be found for very little money, and as medium distance tele's they certainly shine, you'll probably be only limited by your tripod use and atmospheric clarity for optimum sharpness. The ED edges both these by a decent amount but not SO much that the P or P.C are unusable, if you're doing mostly B&W and some color print and slide you'll hardly notice.
Also, don't knock those Pro used thrashed lenses in this length, I've picked up a few amazing deals just because the cosmetics were fairly beat, but the Pro use a filter religiously and consequently the glass was nearly mint, and one I got like this (an ED version) has the most smooth focusing, loose but so smooth, you could tell some shooter used it every day. I think I got it for 35.00 on ebay, a true bargain. Keep your eyes out....