FAQ, I should say (my post wasn't clear) that of the people I know who have barely touched an instrument since they left, most are very unhappy about their experience at Chets and wish that they had not gone. They found the pressure overwhelming, and can no longer take pleasure in playing their own instruments (fnaar), although they do all still take a great interest in recorded music. I know that this is a source of sadness and regret to at least three ex-pupils I know.
This isn't to say that it can't be a great school, but it's difficult to predict which children will do well there. From the people I know, I'd say that maybe non-conventional types would struggle there - if you suspect that your son wouldn't get on in basic army training, for example, he might also not get on at Chets.