Peyton made everyone around him, played with him, or coached him better. Brady had the luxury or already having the players and coaches in place. He's played for the arguably the greatest coach in the history of the game. Brady throws to open receivers. Peyton threw to receivers who weren't open but, better be, once they ran the route he told and expected them to run.
A former Tennessee coach told me back in the 1990's, about a occurrence between Peyton and very talented and promising receiver (If I told you his name I think everyone from that era would remember it well). Peyton told the receiver he needed to attend his(Peyton's) summer practices with him and the other receivers. The receiver chose not to go to any or enough of them. He thought he was good enough already. I was then asked by the coach telling me the story "How many balls do you think Billy got thrown to him in the fall ?". Enough said.
