I disagree with the author's premise that

"Few understand that the SAT requires specific, school-independent training."

I took both PSAT and SAT cold with no specific preparation and did very well. So did my friends. It was even fun.

While I see no _need_ for SAT tutoring, especially for excellent students, I've heard claims that tutoring can raise scores. I would have felt, at the time I took the SAT (and even today, somewhat), that "preparing" was a form of cheating, since those who "prepare" have an unfair advantage over those who did not. It also taints the statistics.

But that was before I read about how physics and mathematics students in the English university systems were sometimes heavily tutored prior to mathematics/physics contests/exams. Having a personal tutor of Nobel-prize quality who drives you hard would undoubtedly sharpen one's skills.

I can confirm that tutoring boosts scores significantly. I went to an SAT prep program that was designed specifically to help you beat the test. My score was 1680 as a freshman and 2390 as a junior.