I, for one, have found that I see more benefits from RE work than DE work. Probably because of the point that Eric brought up about the fact that very few people lift slowly on purpose.

From a "powerbuilding" perspective, or people following somethign that smells and tastes like WSBB but aren't competing powerlifters, I would say that DE work may have limited use in the grand scheme of things. Not that it is bad, but there may be better ways to spend your time.