I just bought three lenses (my new Nikon addiction...) from KEH,
200 F4 AI -> EX
135 F3.5 Non-AI -> BGN
105 F2.5 AI'd -> UGLY
The AI job on the 105 is the only thing that looks kinda shoddy--a couple of lumpy solder-jobs. The machining is fine.
The optics are perfect, focus and aperture feel GREAT!! I paid $50 for it.
Unless you absolutely cannot risk the money, UGLY is a perfectly viable way to get some nice kit, it seems.
That is all!