My male cape, Griffin, is 18 months old. I can't really comment to the one person bird because I am the only person in my household that consistently handles him. I've tried really hard to keep him socialized, so when I am able, I take him with me to family functions and people handle him, and he does pretty well. We haven't hit his "terrible twos" yet, so it remains to be seen how he will be once he is mature.
He is goofy, eager to please, stubborn, an excellent eater, an excellent mimic of sounds and several words, loves head/neck scratches, and gets into mischief. He is my dream bird and is all that I hoped he would be.
If you're on Facebook, there is a relatively active Cape Parrots group that may be able to give more info about mature birds.