Nobody here would turn into a blithering idiot if they went to a comprehensive, nobody is that weak.
I go to a grammar school in Chelmsford and we usually get around 20 to Oxbridge. I used to think it was because the people who enter via the 11 plus were clever but thats just not the case; we have people who are distinctly average, even nationally (some of the people who got in are predicted only 5 passes in GCSE!). But then when I look at people from my old school who went to a comprehensive who were good enough to get into my school at the 11+ age, the best they're going to get is half A's and half B's, its crazy!
To be perfectly honest, even though its unfavourable to my chances for Oxbridge, I see no difference in the supposed 'coaching' private schools give you and what my own school and most grammar schools also do yet they are discriminated against and we (the grammar school pupils) are not. Seems stupid to me. It's all to do with image I think.