Hi,
We have recently got a hand-reared Hahn's, and he is our first ever parrot. He is generally quite a good bird, and we have not had any problems (yet! - it's early days!). He has a definite preference for my grandmother (purely because she is with him all day every day) but will happily sit on other people when she is not around, and is not at all defensive of her. The only thing is that he doesn't quite understand that nibbling people's fingers can hurt!
They are quite active little birds, so be sure to buy a big cage where it can take flight, and let it out daily.