I agree that it depends on your child. I haven't been, but I bet my 2 daughters (ages 6 and almost 2) will enjoy it. They like football games, pep rally's, fireworks, and think it's funny when I try to scare them. I say you know your kids best, and if they're sensitive to things like that, then maybe Fantasmic isn't the best thing for them. I'd try it out and see, perhaps, and leave if they don't like it.
Susan