The lower-performing selective schools (ie, NOT Ruse, Baulko) are the best ones. They take the best of the whole academic excellence thing, but it's not so competitive. At schools like Girraween, you also learn how to be a good Person, since you're working With your classmates for the best marks, not working Against them. Sure, the averages aren't as high, but who cares? Marks aren't everything.
My favourite example was when my year competed against James Ruse in a men's volleyball game. James Ruse did all their girly warmups, running around the court and acting like a professional team. Girra just sat around, had a few laughs, then proceeded to slaughter the bigger and stronger JR team. Final score 36 to 8 Girra, because while the JR team were bigger and stronger, they were all competing against each other to be the dominant player of the game, while the Girra team were working as a team for the collective good. Moral of the story? It's no use being the best at something, if you can't work with other people. Employers look for team players, not academically brilliant people, and JR are definitely lacking in that area.