I'm very familiar with cockatoo's And very familiar with different Goffins. Tara's former Goffins Goofy started out being the sweetest most loving wanting to be held bird, Then there was a break in at the shop where he was living and from then on it was down hill. We don't know what happened that night of the break in but what ever it was so totally affected him that he was never the same sweet loving bird he started out to be.
I've seen several other goffins do the same thing just go kind of schitzoid and pluck and mutilate...none were related to hime either...
I've also seen some very sweet and loving adult birds, but its been my observation that while they can be sweet and loving, just the slightest little change can send them over the edge.
Cockatoo's as others have described are a leech with feathers. They would stay on you 24/7 if they could but remember they don't do well with change. Cockatoo's seem to be worse than any other bird in that respect. What happens is; because they are so sweet and loving and want your attention when they are young and really really cute, we humans have them out and are holding them every possible minute, then the new wears off or your schedule changes...life happens...and then the bird starts getting less attention. They start doing what ever it takes to get the attention they were used to getting...and it doesn't matter to them if its negative or positive attention...attention is attention. Also as they mature males can become pretty agressive...females too. They get louder and louder with flock calling and I'll tell you right now, just because a goffins is small doesn't mean it doesn't have a loud scream... Also while they may have one of the smallest beaks of any cockatoo they can still do a lot of damage. Both to human flesh as well as anything else they decide looks interesting.
If you haven't already, you might want to visit this site
http://www.mytoos.com/ Make sure you turn your volume all the way up...so you get the real effect of a cockatoo...Yes, even a Goffins can be this loud. Not generally but it is possible.
I'm not trying to talk you out of a cockatoo...I just want you to go into it as well educated as you can possibly be. While I think they are amazingly beautiful birds. Very intelligent birds, they are very very emotional and needy birds. And honestly, Of all the birds I've ever owned or come in contact with, I feel cockatoos of any subspecies would have been far better off being left in the wild. I truly believe that as a whole cockatoo species has been so messed up by the involvement with humans. It truly does break my heart to see what happens with so many of them because people don't take the time to research and learn what there is to know about these beautiful creatures BEFORE they get one.
I'd bet I could safely say that for every 1 sweet and "normal" pet cockatoo's out there, there's 1,000 that are so totally messed up that it isn't funny.
If you can, go visit a sanctuary or cockatoo rescue, and see what can and does happen with these beautiful creatures. And if you think that "This won't happen to/with my bird" think again,
As I said, I'm not trying to talk you out of it...I'm just wanting you to do Lots and LOTS of research before jumping in with both feet.
Good luck with your decisions