LOL! By "beefier" I dont think they meant to just render it. :p
What they meant was, try to make the body a bit thicker, give it more mass. Right now, it looks a little on the thin side. Think of it in terms of helicopters. Right now what you have is one of those classy, corporate choppers when what you want is one of those bad ass APACHE helicopters.
by the way. got a link to that concept artists site where you got that pick from?
Professor of Digital Arts
Digital Media Arts College
Boca Raton, Florida