I've had a used 863 and more recently I had a used S185 and liked both. I would say that those hours make the 863 sound good, but don't overlook other things, like how they were maintained, what they were used for, how they were stored and what other features they have.
Can you get the maintenance history, or else look at things like looseness in the pins?
How about rust damage beyond just surface stuff. Over time, rust can make seized fasteners a real challenge. Looking under the cab, is it full of dirt, mulch, manure, mud, rust, oil leakage?
How long has the current owner had it, and was it used for loading and things that are pretty easy on them, or for demolition and cement break-up tear out work, that can be pretty hard on them?
Does it appear that there are make shift replacement parts or missing parts?
Is it open or closed cab? Heat? A/C?
Is it responsive to the controls, not lagging in the lift or tilt, and nicely responsive to forward and back.
And, why is the current owner getting rid of them? Is it a good plausible story.
Good luck