Were you asking about the character meal or dinner? I have never been for dinner.but I will tell you this about the character breakfast/lunch
It is not quiet and relaxed. They stop every 1/2 hour or so so to do a dance along with the kids in the front of the restaurant - usually about 2-3 songs. Kids are running up to the front dancing with the characters and the music and voices are pretty loud. (The parents will mow you down too, but that's an entirely different post) They also do a conga line around the whole restaurant and have the usual character visits. Only you know your child, but if he does not do well with a lot of stimulation, noise, action and people, this is definitely one to skip.
I'll see of I can find a picture for you. I think there's a thread with inside restaurant pics somewhere too...