We have a an African Grey that my wife was given before we were married. It's a rescue bird, so it has some issues. The larger parrots will more likely be louder, and smarter. They need a lot more time and interaction than some other birds, plus more space. They really do have the intelligence of a child. They can talk, ours understands context, not just mimicking. If they get bored, they can get incredibly destructive, to themselves and to their surroundings, as in you and your house. They will generally get along good with most people, although some birds have issues with different genders. They will really attach to one person. And it's likely that that person will change once or twice as it matures.
It is totally worth the time and effort for us. Ours is part of our family just like Red Devil said.