If you stood me in a costume next to a computer graphic of the same-looking character, I think there would be a difference. And many movie fans I've spoken to would rather see an actor in a costume than CG.
“In the beginning of the human race there was no genetic load which would cause undesirable traits such as appear in offspring of marriages between relatives today.”
“I have four kids; three girls and a boy. The oldest girl is 13, and has her own social life now, so there's a bit of begrudging cooperation there. It's tough.”