I think there are very general statements that can be made about different species of toos but I don't think you can lump a species together and say this one is sweet, this one doesn't pluck etc because it depends on so many factors. As Icey mentioned environment plays a big roll. There are factual things, like a Moluccan's scream is one of the loudest. Goffins are known to be very mechanical. Galahs voices are softer than a lot of other cockatoos. The cockatoos that are needy are because people made them that way. If you read about how cockatoos are raised in the wild and then how they're raised in captivity, we have created the neediness in cockatoos. That's not to say that with proper training, etc that can't be corrected but most people don't have the dedication, determination, aptitude etc to work with cockatoos. So they unfortunately get passed from home to home. Cockatoos are amazing. My goffin is my best buddy. He is a wonderful bird for me. I am his 4th home that I KNOW OF. I believe he had at least one more than that if not many more. Any cockatoo is a commitment. You have to be willing to really learn about them and work to understand them. I don't know if any cockatoo is really "easy". They're smart and will test you. I am very much team cockatoo and completely love them. But they need a large cage, lots of enrichment, a proper diet, training and attention. There are many, many cockatoos in rescues. So, I would check rescues near you and try to meet some if you think you want one. (And I don't want to make it sound like rescue birds are "problem" birds. They're not. Many are there because their owners were elderly, had to move, the chlld went away to college, the owner really didn't know how to take care of a bird, etc.)