Here's the thing about Missouri, and I've been saying it for a long time. They recruit talented players and do a pretty good job preparing for teams, but they have two issues.
1) Their run game is too laterally based. Most of the their hand-offs begin with the running back running laterally before making a cut up field. They have no downfield running threat, which means that a team that stays within their assignments will easily stuff their run game. They struggle against big time opponents because they just aren't physical enough up front in the run game.
2) Their pass defense is generally atrocious, especially this last season. They have solid linemen and a linebackers (like Spoon), yet their defensive backs have a lot of trouble. If you look at the way we played in the fourth quarter against them, 2 of our touchdowns came off of blown assignment. The other touchdown pass came because neither of their backs tried to make a play on the ball that Paul caught.
I believe it all simply comes down to coaching. Missouri recruits talented guys, yet it seems that they don't develop into stout defenders in the back field. Their offense will keep them in games and in the North title hunt, but until they get those two things fixed, I don't think they'll ever be able to challenge OU or Texas in a Big 12 title game.
So, in the end, I'm not too worried about Missouri. I know they're talented and that they will compete, but they have glaring issues that need to be fixed.