my redfoot, junior, is great. he can definitely tell the differences between people, and his comfort level/squirmyness varies accordingly.
he's pretty smart so far, too, especially for a baby. if he eats something he doesn't like, he remembers it later. once i'd painted my nails blue and, thinking (i suppose) that it was blueberries or something, he went to eat them 'til i wiggled my fingers and he figured out it was me. after that he totally ignored my nails, so obviously he learned something.
he's pretty docile, too, really. being captive-bred helps with that, but he hardly ever shrinks away from anything unless you move fast, and then he's right back out of his shell when he realizes it's ok. the only time he pulls all the way in is when i bathe him (every once in a while i gently clean his shell with an old soft toothbrush).
i'm sure lots of the regulars here can tell you some good stories!