a friend of mine whose son is going into Y8 there did say that he struggled intially cf private school children who had indeed had a wider education than the one provided through the narrow funnel of the NC. However she is a teacher and takes it all in her stride (her daughter went there too and has just got a first from Cambridge) saying that all that evens itself out by y8. Try not to worry, I'm sure it will all go fine.
My boy didn't do spectacularly well academically in his grammar in Y7, it was such a culture shock (up at half 6 rather than 8.20, bus ride, homework, kids from 60+ other primary schools etc etc) but the delightful head of year doesn't care at all, says Y7 is for the social side too, that he's thrilled to see my boy always chatting and laughing and surrounded by people and that that
is important too. I've given him this year off, so to speak, but will expect more application next year. His intelligence isn't in doubt but, for him, there's so much more to life and learning than Motte and Bailey castles. We need to find a balance (!) but as in all areas of life, it's a learning curve and it'd be dull if it all just slotted into place perfectly from the off. Please say it would be dull