My son went to one at San Diego several years ago. Well it was the day camp, I think he was 8. He loved it. He was in a morning camp and did the afternoon fun session. When I picked him up we would tour around the park until 8 oclock showing me what he had done during the day. So he was there open to almost close for 5 days.
Absolutely recommend it. My son has always wanted to do it again, sometimes it's hard to plan since we're in Canada and it's a 2.5 day drive.
He would love to do the resident camp now that's he's old enough but it's so much money. I told him he could do the camp and I'd do a 3 day cruise - that didn't go over well.