Hi, madeinuk,
I can only speak to my dc's experience after 6th grade. Dc had scores in the CTY high honors range in verbal and math (I don't know what the CTY cutoff is, but dc had 95+percentile in both as a 6th grader on a test normed to 9th graders), and dc was excited about studying science with other smart kids. There were definitely some kids there that matched him or exceeded him in math ability, but there were also kids who, at least by their own report, had 60th percentile scores on the relevant tests. We were able to see the written work product of all the kids (posted on a website), and it was not impressive. CTY also let in a couple of 4th graders who had a hard time because they were so young -- and made it hard on those around them (not their fault, but they were needy and there wasn't all that much supervision -- just some very tired, though well-meaning college-age RAs, about one RA for 12 kids or so). So it wasn't the high point we had hoped. I know others have had better experiences. One issue, in retrospect, is that 11- and 12-year-olds may not be ready for sleepaway camp in college dorms with RA supervision. The RAs were kind and "cool" but clearly weren't parents -- they didn't "get" that you don't get to go to bed and shut your door at 11 if any of the kids are awake, homesick, crying, fighting, whatever! :-) So there was a "Lord of the Flies" dynamic at night that was hard too.
