Let's get this out of the way right now: I am a completely irrational Peyton Manning fan. The cerebral way he picks apart defenses, the precision, the way his study altered the way a large portion of what quarterbacking means: I'm a fanboy. Tom Brady has the better record, but also has the better coach. Brady also has a much more standard relationship: he might have the authority to audible, but for the most part his coordinators give him a play, and some options out of it, and use one-word schematic changes if necessary.
Not so with Manning.