Actually, we had the opposite experience. My 4 1/2 year old DD was positive she wanted to ride. Since it is my favorite ride, she wanted to go on it during our last trip because she was now "tall enough." I showed her a lot of pictures and videos before we left so she would understand what the ride was like, thinking if she got a glimpse of the ride she would change her mind. But when we got there she still wanted to ride, and against my better judgment, I let my DH talk me into letting her ride with us.
During the pre-show she put on a brave face, telling me I would be ok and not to be scared (I think she felt braver "comforting" me), but as we neared the elevator doors she was becoming more uncertain.
By the time the elevator doors shut and we took off in the dark...yikes!!!
Nobody on that elevator enjoyed the ride that day
You know your child best, and my advice is if they are at all afraid of the dark and/or confined spaces or ghostly images, save TOT until they are a little older. I wish we had.
MsSpinShady