Who is the 49ers defensive MVP at the quarter mark?

Today in our Golden Nuggets, James linked to an article from Taylor Price, who answered Twitter questions. Asked if it were appropriate to consider Perrish Cox the team's defensive MVP at this point in the season, Price acknowledged that Cox has been playing incredibly well. Noting that Cox had to step into the starting lineup, Price argues that Cox "deserves a ton of credit."

Price also noted that a few other players have been exceptional on defense, offering Patrick Willis and Antoine Bethea as alternatives. And, they are worthy players of the informal honor. Willis has been a tackling manic on the field, notching a team-high 23 tackles in addition to two pass breakups and an interception (lol romo). Bethea almost single-handedly shut down the Philadelphia Eagles' offense, so he is obviously playing well.

But, it's one other player that Price offered who, I think, deserves the title of Defensive-Player-of-the-Season-So-Far: Justin Smith. Price gives the component stats. Justin Smith has 13 tackles and leads the team with three sacks.
Those basic stats don't get Smith's major contributions across, however. Well, they do halfway. The three sacks have not only come in a season that has been rough for the pass rushers on this team, thus making Smith's contributions all the more important. But, the sacks have also come at key moments, slowing down the opposing offense just when the 49ers needed it.

The tackles, however, don't show how effective he is at anchoring the line against the run. Now that DeMarco Murray is running rampant against everybody, the defense doesn't look so bad against the run. And, Smith has been a huge part of that. With NaVorro Bowman out, the front seven needs huge contributions from their key players.

What about you? Let's consider the same question: is Perrish Cox the defensive MVP considering his unexpected play? If not, who is? Can I get a little Justin Smith bandwagon going on?