I got my bird while working at petco, it was an impulse that couldn't be denied. I knew little but had to have one. I had a chance to handle a couple then when I got the overwhelming urge to get one we had four recently come in. I had the chance to handle all four, two wanted nothing to do with me and two were amazing. An impulse told me I wanted the peach but when I came in the next day she was gone. I got my bird and she's perfect short of being spoiled and screaming at me when I leave the room (still working on that).
I would imagine that you can pick up on a birds personality pretty quick no matter where it comes from. I'm pretty sure our conures were hand fed from wherever they came from but still. All 4 of them sold fast as did the rest when I worked there, even the ones that would bite rather then step up. If you want to work with a bird it will work with you in my experience