DS1 goes to a fairly deprived comp. 35% GCSE pass rate last year. DS2 goes to a SS grammar.
They will both get extremely good GCSEs. Possibly identical grades. But there is no way they're getting the same education.
For example DS2 has 1 maths class a fortnight where they don't follow the curriculum but just prepare for the UK maths challenge. DS2 got a gold in that but DS1 didn't even sit it.
Ds2 has been exposed to Latin. DS1 hasn't.
DS2s education appears to me to be superior in every way. Better sport. Better music. Better drama. Better SEN support (they are both on the SEN register for Aspergers)
DS2s school has very few FSM pupils. it also has almost no white pupils. 3 white pupils out of an intake of 150.
DS1s schools is still excellent. His SEN has been well supported and he will get the grades to apply to Oxford. But it's still not as good as DS2s school. He still hasn't learnt as much as DS2 has.
And I don't think that's just down to the fact it has more deprived pupils. I think it's down to the fact it doesn't have many bright pupils.