Being in MN and watching the Vikings regularly, IMO the Vikings are NOTHING without AP.
I mean NOTHING. No offense, because they have nobody else with Harvin gone.
No defense, because of a lack of offense the D would be on the field all the time and would be fatigued so much that they would completely suck.
No kicking because lack of offense wouldn't give them any chance.
No punting because no offense means you will be punting out of your own end zone all the time, which is nerve-wracking and nervousness produces inconsistent punts.
How far would Denver, NE, or GB fall without their QB? All the way, of course, because there would be nobody to manage the ball. In that sense, a QB is always intrinsically more valuable than any other position, including a RB.
When talking MVP, I think the discussion should be how much improved the team is, relative to having an "ordinary caliber" player substituted for the one under consideration.
Using that metric, I don't think any team would fall as far having subbed for any single player, as would the Vikings having subbed for Peterson.
Just my 2 cents. I like AP. He goes hard on every single play. He had the same surgery I had. He's fast, and he's not afraid of contact. Maybe I can organize a charity race here instead. I'm sure he can beat my mid-11, even though he's optimized for cutting and toughness!