I'm a huge Pat's fan (live and die with them), and Tom Brady is my favorite Patriot ever, but I still say the greatest QB I've ever seen is Joe Montana. 4-0 in SBs and had 11 tds ZERO INTs in those games, the most pressure filled games.
4-0 in Super Bowls is great, but the analysis is incomplete because he played in 14 seasons, not 4, and you also have to account for those other 10 seasons.
Brady needs a 4th ring to be above Montana in everyone's mind, granted, but we would still hear, even if the Pats won this year, that "4-0 is better than 4-2"
But look at it this way,
if the Pats were to win this year, compare the top 8 seasons of Brady and Montana:
Brady:
4 championships
2 losses in the Super Bowl
2 losses in the conference championship
Montana:
4 championships
2 losses in the conference championship (didn't get to the Super Bowl)
2 losses in the division round (didn't get to the conference championship)
Their top 4 seasons would be equal, their next 4 season would be in every single case advantage Brady.
take it further, to the 3 times Montana didn't even make it into the playoffs, vs. one for Brady (this omits Brady's injury year in 2008 and Montana's injury year in 1992)
In other words, it is silly to think that losing in a Super Bowl game is somehow far worse than losing in an earlier round and thus not even getting there.
By the twisted logic of "4-0 is better than 4-2", one would have to think that a Patriots loss this Sunday to the Broncos is BETTER than a win would be, if the win is coupled with a loss in the Super Bowl.