I picked up the D1X last summer. Amazing how the prices of bodies deteriorate...when the D1X was new (circa 2001) it retailed for $8,000; I picked mine up for $300. Very nice body, though I wish it had interchangeable viewfinders like the F5 did.
Ever since I bought a Katz Eye screen, i've been much more open to buying older non-AF lenses. In fact, this week i'm probably going to be looking at picking up a 400/3.5. Nice heavy, metal lens. Doubles as a club if someone ever tries to jack it from you!
I wouldn't trust those plastic mounts at all either, the 18-55 kit lens (that came with my D50 when I still had it) was a plastic mount. As someone who habitually picks cameras up from the lens, I could see a heavy mofo like a D1X or a gripped D200 breaking the mount off.
edit: just for kicks, some D1X awesomeness: