I know of several boys who have gone there at 11 and 13. They all seem to be happy and thriving. On the whole they were boys who either didn't take the 11+ because there were doubts as to whether they would pass or those who took it and failed. However, I also know of two who had places at RGS and chose Claire's Court instead. Both did well, one stayed on for Sixth Form and the other moved to RGS 6th.
Very keen on sport, especially Rowing, Sailing, etc due to it's location near the river. I think, though that they have to bus them to playing fields but I could be wrong.
Discipline seems good and they crack down hard on bullying. Expulsion has been known when necessary!
Obviously, this is all second hand from friends but hope it helps.