Groovastic,
You've asked a question that can polarize the forum. There does seem to be a bias towards very long, very stiff boards with a high side-cut radius number. And yes, there are a lot of perfectly groomed pistes in America where you can let a long board go very fast. One question is: Are these long boards being used on mainly flatter intermediate and beginner pistes? You will have to ask this question to those advocating the long boards.
My favorite all time board is a 180 with an 11m side-cut. That board is stable yet I can turn it easily. I enjoy making complete turns more than pointing a board down the hill so I enjoy smaller side cut radius. I also enjoy steeper runs. I have a shorter board, 158 and an intermediate board, 168 and a longer board, 180. I enjoy them equally and make different size turns depending on which one I am riding. I consider all my boards to be "good stuff."