Sorry seeker but I just don't think DS would be appropriately educated if were in a top set at a comp (at least in some subjects).
There would be no point for him to be doing the GCSE sylabus in certain subjects. So why should he go over and over it? That's hardly a recipe for promoting passion in a subject, is it?
And why should he do extension work in his spare time? In his spare time he has PC games to play and crisps to eat!!! And he's a chorister which at his school is A Big Thing. And he plays a sport out of school which takes up a fair wad of time in training.
And anyway, who would do this extension work with him? Teachers are already up in arms about Gove's proposals to extend the school day, why would they want to spend Saturdays teaching my DS?
And here's the thing. My son is catagorically not a genius. He is not gifted. I have a friend with a child like that and DS is not remotely similar. But because he has been around peers with a similar ability and interest, his ability and interest has grown and grown. The collegiate atmosphere has done what yellow described and normalised DS academic abilities.
Now I'm perfectly happy to pay for my DS to have this. And lucky me I have money and a flat in town where we can live during the week so DS can attend his school of choice. But for those kids who don't have that, surely super selective grammars are the way to go?