A few years ago I spent the summer on the west coast and got to snowboard at Whistler and Mount Hood. Whistler kind of blew during the summer. Mount Hood had much more trails, longer trails and a half pipe.
Whistler is an awesome town and has tons of other things to do. Sorry I can't help you put with the camps because I know nothing about them, but from my experience between the two Mount Hood is a better mountain for summer conditions. I have never been to the third place so I can't give my opinion on it.