If these schools are "better" it is because parents are clamouring for places, thereby artificially raising the standards. Left to their own, the number of faith schools would dwindle dramatically. There are nearly 5,000 C of E schools, most of them oversubscribed, yet bottoms on church pews are falling (save for a lot of red-faced couples and their 10 year olds). I have nothing against faith schools by the way.
Grrrr it's that time of year again!