I don't know. It's just hard for me to judge. Everyone wants to look at playoff and team success as a measurement of how good a QB is. I think that's silly. Yes it's a passing league and the QB has the greatest impact on a team's success but it is far far away from being an individual effort. I feel like people don't take that into account these days anymore.
Statistically, Manning has been better but everyone seems to forget that. Everyone likes to key in on a few memorable plays for Manning but that doesn't mean he's lesser than Brady. People forget because of Brady's late game heroics but he's had some pretty bad games that have cost his team game in the playoffs. He's also had some pretty bad games in the playoffs and had a good enough team to get through anyways. Manning hasn't had that luxury. Manning had to play perfect with a horrid defense or they would lose.