I wholly agree with what Richard has said regarding Sea World, I think it is the better of the main 3 parks on the Gold Coast.
Last year I was lucky enought to be granted free entry to all parks on the Gold Coast (Sea, Movie, Dream, WnW, PC) and after going to Sea World the very first day we went to Dreamworld then to Movie World and were meant to do PC and WnW but because we enjoyed Sea World so much we forfeited those to go back which was nice of them to allow us to change prior arrangements.
We would be representative of the young family demographic.
I think Sea World is a park not to be missed because of it's fantastic variety of animal exibits and shows with more than decent rides to mix it up a little. The location, layout and lack of imposing facades/seemingly confined spaces are second to neither of the other two parks.