Product is the only real criterion for judgment, isn't it? There are people who are really, really good at design, but who are almost completely unaware of the rules they intuitively follow, and there are others who've spent years (or decades) learning the rules, the history, the trends, and can write long, scholarly papers about the subject, but who cannot create anything original. (I fall into the latter category, by the way -- but at least I'm aware of it. Enough people are pleased with my reiterations of past successes that I'm not too disappointed with the rut I'm stuck in. And there are few surprises in store for the clients when they are free to ask "can we have that one in blue?")