Aldon Smith is a stud no doubt. Even if he ends up with more sacks than Von, I still think Von will get more looks for DPOY.
I look at it as, Smith is just another cog in an excellent 49ers defense that Justin Smith, Bowman, and Willis allow Aldon to just rush the passer. i.e. Aldon is not solely responsible for how good they are.
Von, on the other hand, can be looked at as the player single handedly elevating our defense to top 5 contention. While we have other impact players, I would argue that Von receives most of the scheming and game planning against as we don't have the likes of a Bowman, Willis, or Justin Smith on our team (let alone all 3).
In the end, I could care less. I just hope Von remains injury free and I look forward to building around him for the next decade and watching him beast around every Sunday.