DS is not anything close to a math genius. I agree that the SAT would not be a good measure of that in any case. I also tend to think that SET is also premised on the idea that if a kid can score 700 without all that formal instruction (Algebra I and II and Geomerty) that a college Junior is presumed to have had, then he might have some measure of talent.

As for the length of the test, it is grueling even with the breaks and downtime, but the actual test is well under 4 hours (70 minutes math, 70 minutes reading, and 60 minutes writing with a 20-25 minute expermental section thrown in).