I think he'd be a good age to go. There is plenty to do that he'll enjoy and Disney is set up so that if the grown ups want to ride they still can. At most all the rides when you get to the front of the line they have a kiddie area, where a couple family members can stay behind with the kids while the other grown ups ride, then right after their ride is over the few that got left behind with the kids swap out and get to go on the ride next. I'd try to plan it though during off peak times and when the heat and humidity isnt as bad.