Well, I'm glad Nathan is happy at the Davidson school; I wish him all the best. I would second HK and Val's points, though, and particularly echo the idea that high IQ does not equate to success or to happiness--the one I remember best was from Malcolm Gladwell's Outliers, which is summarized here (and perhaps is in reality a little different from the description in "Outliers" depending on your perspective, although Mr. Langan does not seem to be terribly unhappy)
http://en.wikipedia.org/wiki/Christopher_Langan

Finally, I'm not sure what Great Schools has to do with any of this. In our area, the only presence I'm aware of is that Great Schools has a website where people can post anonymously about particular schools--with predictable results. You might as well go to Yahoo to find a school for your kid, or flip a coin. I'm hoping Angies' List starts reviewing schools, although it still wouldn't be very useful to us because it has become clear that the results completely depend on the teacher(s) and whether they are interested in helping your particular child.