I know the Childs family personally, John, their father/grandfather was one of Wales' best, he conducted Tredegar band in which he brought up Robert and Nicholas on Euphonium....... Robert moved to Grimethorpe Nicholas went to Frickley, the rest is history, both turned out to be the best in their profession, David (Robert's son) also took up the Euphonium and in his playing has many of his grandfathers qualities, as to who is the best, personally I would go for John but that's just the view of a sixty-two ex-soprano player....