I live in a big city. Lots of kids travel a long way to go to 'the right' school for them. I am not sure I want my DC to have to travel so far although those who do get used to it pretty quickly.
Nearby we have one academically excellent school and one goodish comp. 98% of the kids in the academically excellent school are of a different racial origin from DC and his current friendship group. This difference is about 50% in the goodish comp which is a more accurate reflection of his current friendship groups.
Long term would it be bad for DC to be massively in the minority in this sense or is it irrelevant? Some of my friends are not even considering the academically excellent school because of the ethnic issues. Is this a wise decision?