Talk to parents at the schools, especially those who have had a change of head. There are two C of E primaries in Twickenham with new heads. One on the way up from "good", and the other on the way down from "outstanding".
Talk to the parents whose children attend the school -- but perhaps not the ones who are also employed by the school.
Most people I know were given their first choice. We are number 1 on a waiting list although are also considering private Primary schools now too. What do you think- are outstanding Richmond primary schools comparable to Kew private primaries? I am finding it really hard to choose between them, can see pros and cons in each.