I think the enthusiasm to work quality correlation is pretty universal; I also think most businesses only grasp it vaguely, at best, and are used to accepting poor work from most employees. Do you know which variables matter to your enthusiasm? I know it can often be a circumstantial thing, but even poor hints are better than none at all.

Also, get me answers to the questions I posted in that link: I've got a fair idea of your skills, but I'd rather rely on your self-assessment than my second-hand judgment.