No stat is perfect, but I tend to prefer total yards to points when it comes to ranking a defense. Teams can give up points on offense and special teams, but they don't give up yards. And yes, I realize that field position, time of possession, and other factors that aren't directly attributed to the defense enter into the defensive yard's equation, but it's closer to the mark than points.
Having said that, at this point in time, I firmly believe that our defense is the best in the league. I'd rather have our D out there than D's from Houston, Denver, Minnesota, Cleveland, and the Chargers, the teams that finished ahead of us in fewest yards allowed.