They are often sweet and affectionate--they can be so much fun in the right setting. Tame isn't the biggest issue, so much as neuroticism, screaming and plucking (when bored, or away from preferred person). In a car or small room, my U2 is an angel (mostly). She wants to be with me wherever I am, which is sweet, but obnoxious (and while flock behavior, certainly unhealthy in a human world). They take things very personally and they get upset over absences etc. They are very sensitive and when they go into self-destruct mode, look out! Mine has never gotten to that point, but if you look online, you will see that the majority of Toos have a collar around their necks to prevent them from tearing their own skin/plucking feathers. This is not a "normal" behavior, but it seems to be the "norm" for many, if not most, captive "toos".
They live for so long, that that sensitivity often works against them...Not always, but often.