Andrew, the guy who wrote that article is talking at cross purposes. The idea of Power Rankings being determined by dominance v. guttiness is not the point. He writes:
People want to believe that the teams that can win the close ones are championship teams. But as counter-intuitive as it sounds, championship teams are generally defined by their ability to easily win games over inferior teams.
Yes, but that isn't my point. You have to be able to win close games over good teams and, yes, if the situation arises, beat average or below teams in close games, too. We couldn't beat the Rams this year, and by his logic we shouldn't even consider ourselves contenders, yet here we are, pretty close to the big game. Let's look at some of the dominant teams:

Patriots last year: in their wins, they often won big. In the close games--including the Super Bowl--they lost more than they won.
Patriots 2007: They only played a few close games all year. Against a really good team in the biggest game, they didn't find a way to win. They didn't have a lot of experience with having to.

On the other hand, in '89, 4 of our first 5 games were close, and we won 3 of them, then won another close one at the end of the season.
In '84, one of our most dominant teams, 5 close wins.

My experience is in tennis. One mark of top players is they know how to win when they are not playing well. (Like the Pats against the Dolphins a few weeks ago.) My pick for one of the best teams next year? Seattle. They played a ton of close games. They learned how to come back from being down. Then when the offense kicked in, they started blowing out teams. But what makes them tough is not how they play when they are ahead but when they are behind. Teams that have won close games don't ever fold.

No, give me a team that only wins big and I'll show you a team that's ripe for an upset. Show me a team that has won in all manner of ways, that is the mark of a champion. I'm not saying Atlanta is going to beat us, just that they can come back when down, and unlike a bad team in a hole, these guys won't go quietly.