Oh yes, I have been there for the last two summers! It is a very good computer summer camp offered by colleges across the nation. Two years ago I was in the Programming & Robotics course (this year it has been split into two different classes), but unfortunately they didn't use VEX until last year...
But it is very fun for the teens as well as the mentors (or at least, I am assuming that most of the mentors have fun). I highly suggest this camp to anybody interested in computers.
I don't know how the robotics course is now because they just split off from programming. However, when they were still joined last year when they first used VEX, I think most of the kids had fun with it. Unfortunately, they didn't have enough time to play with the robot because they were also programming...
Which site would you be going to?