Would Manning's legacy have been better than Brady if his team had went undefeated and won the Super Bowl?

Both guys have some years left to play (barring early retirement or injury), so it's premature to ess their legacy. When we talk about a players' legacy, it takes years to really see their contribution in perspective. For example, Joe Montana and Terry Bradshaw both won 4 Super Bowls, but the consensus is that Montana was a much better QB between the two - just compare their career stats. Basically, wait until Brady and Manning have left the game for a few years, and then we'll talk about legacies. If you don't believe me, just ask Brett Favre (ouch!)