That's always the question - just b/c a car wins a race doesn't mean that it's competitive if the "usual" leaders didn't show for the event.
I've been racing a 1.8 16v for years (b/c I'm stupid) and the car is far from "maxed out" so it's slow in comparison to at least half the field. That having been said, it's been reasonably durable and it's a veritable tank in a sea of Japanese tin-foil.
I think it's possible to get weight down to minimum but it takes alot of effort and a very thin driver (which ain't me). Even so, as noted, it has the aero of a large brick BUT at least you become everybody's friend b/c you'll find at least 5 cars stacked up behind you on the straights as they draft their way past...