My socially shy, very quiet DD went to CTY at just-turned-11 and 12. She LOVED it, every minute. The kids are kept quite busy and have two sets of people responsible for them - the teachers of their classes during the day, and the RAs on their hall from 4pm until after breakfast. There are activities planned every afternoon between class and dinner, and I think most evenings after dinner as well. We had medical issues that required phone contact every day, but she barely had time and wanted to get back to... whatever it was she was doing, braiding each other's hair or creating a scavenger hunt for another hall or something.
The second year, we convinced an acquaintance from school to apply. She had never attended a sleepaway camp, and had only been on a sleepover with a friend once because she would miss her family too much. She had no problems and loved it possibly even more than my DD. (They did not end up in the same hall; both were surrounded by entirely new kids.)
I understand that each campus has its own culture, so you may want feedback specifically from the campus you are considering. PM me for our campus and details on activities there..
