Yeah, a clown tang would easily dominate a 1000 gallon tank. They're so cool looking, but tank requirements when they age is insane (you probably have to do it to, otherwise they'll just say ha ha to you and destroy the other tang/fish).
It really is their personality based on the fish though. Most get nasty. The poor track record on clown tangs is the fact that they're usually caught with cyanide. Probably why you see very little in aquaria. This is based on what I've read on this board though.
In either case, both clown tangs' for both owners - they look healthy and full of color anyway.