First of all, Peyton has to actually win it. If NFL history has taught us anything it is that a good defense will beat a good offense. The Seahawks have the best defense but for the sake of this conversation lets assume Peyton leads Denver to a victory. Peyton will now have two Lombardi's to Brady's three. After double checking the math that leaves Tom Brady with more. Although a simplistic way to look at it, Super Bowls have long been the measuring stick for QB greatness. Yet a debate between these two Hall of Famers cannot be so open and shut.
With things having gone according to plan, Peyton will have to open up some room on his trophy shelf in a little more than two weeks. Not only will there be a Lombardi to place but probably another Super Bowl MVP and definitely another league MVP. That would technically bring Peyton to 5 NFL MVPs but there was that one he shared with Steve McNair. Tom Brady only has 2 MVPs. Clear advantage to Manning when it comes to regular season greatness. In his two record breaking seasons, Peyton threw for 104 touchdowns combined, take a second to think about that.... When it's all said and done Manning will probably have all the passing records in the book. The man was born and bred to be a quarterback and you would not need an oracle to see the success he has earned coming.
Clearly Peyton has done all he can to be considered the best QB of this generation and this Super Bowl win would solidify that case. With little to separate these two it is what we cannot quantify in numbers or measurements that will give the edge to Brady. Intangibles; sure Peyton has them too and has displayed them over and over again during his career but the adversity Brady has dealt with and overcome to even be in this conversation is what the NFL is about.
Since we cannot technically measure this value a fun way to look at it would be to switch the teams around each QB and look at the results. Tom Brady is taking that Denver team to the Super Bowl with all the records, not a doubt about it. Peyton Manning however does not get the Patriots to the AFC title game. Why you ask? Well Peyton has never managed an undermanned squad to that point in a season before. Tom has. In fact Tom has done it a plethora of times, with either insufficient offenses or non existent defenses. Peyton on the other hand lost twice to the Patriots in the playoffs after being league MVP. While football is most certainly a team game, the type of team around one of these two QBs hasn't mattered to him having success. If the numbers have been virtually the same and the statistics can't separate them for you ask yourself; would you rather have the QB that wins with great players or the the QB that wins with anybody?