At the end of the day, this goes back to our school choice. The magnet school program advertises as catering to "extraordinarily gifted children" and has a requirement that students test at least +3SD on the WISC or its equivalents. They make a big deal about how special the kids are, which may have colored my perception. In retrospect, I don't think 3SD should be deemed extraordinary (but I've also accepted that this language can be viewed through the lens of puffery).
Since posing this question, I have asked some parents of the program about their kids and it's in concordance with the views expressed in the thread: no observably obvious Terrence Tao-types (not a big shocker ex-post). We're still trying to figure out whether the school is a good fit so I don't have much to add at this point.
Finally, in terms of our child, the WISC revealed very balanced scores across the 5 categories (on a relative basis, VC, VS, and FR were the strongest, and WM was the weakest). Our day-to-day observations are that she is 1) excellent but not "extraordinary" at a variety of academic subjects 2) very advanced in terms of social-emotional development/control than her peers (observed by us and the teacher; she is most comfortable talking to adults). The one "talent/passion" that we've observed and cultivated is music - she is extremely advanced in piano and violin and has also started the cello, the latter of her own volition.
That's probably more information than anyone cares, but I just wanted to help the posters understand the basis for my question.
+3SD is approximately 1 in 740, whereas it has been suggested that Terry (whom I will always remember as an adorable nine year old at NMSS 1985) is the most accomplished mathematician in recorded history, which would place him around +7SD (at least wrt mathematical achievements).
