Hi -
Ds12's school encourages qualified students to take the EXPLORE, ACT and SAT every year through a talent search, but I stopped signing him up for it last year and registered him for the SAT through our local high school instead. My main beef with the program is that the 'analysis' that comes back with the scores is generic, and IMO not worth the money, especially since score comparisons and analysis are available online for free.
The money we saved was more than enough to pay for the SAT's question-and-answer service, which seemed way more useful.
My main purpose in having him take out-of-level tests has been not to use the scores to advocate, but to track improvement year to year, to be sure he's in a good learning environment.
Ds hasn't gone to any of the summer camps, but has taken 3 online courses through the talent search program, and for the most part we've been pleased with them.
One benefit of SET you may not be aware of: members can order a CD containing reviews of dozens of colleges, submitted by SET alums. I will order it in a couple of years for ds, so he can find out what kids with abilities and interests similar to his think about some of the schools he's interested in.