I'm rather proud of myself - my model of 31171 won the Locomotives class in The Chairman's Cup at Scaleforum. A model which was predominately RTR bits, was considered alongside kit and scratch built steam locos. It shows how far diesel modelling has come along and how it's now regarded. When I put a class 37 (a hugely modified Lima body with correct tumblehome and a chassis which used Hornby class 50 bogies with a new motor, etc., etc...) in the competition (around 2005 I think), it was only allowed into the modified RTR category, not the full locomotive one!
I certainly think that The Scalefour Society is very much moving in the right direction and is a very relevent and vibrant group which supports good modelling regardless of the subject matter.
There's more about the model here - Project 31.