Peyton Manning, first 5 years starting(1998-2002):
1749-for-2817 (62.1%)
20,618 Yds (7.32 Yds/Att)
138 TD/100 Int
85.9 QB Rating
Brady, first 5 years starting(2001-2005):
1576-for-2545 (61.9%)
18,029 Yds (7.08 Yds/Att)
123 TD/66 Int
88.5 QB Rating
Statistically they are pretty close. Peyton threw more for more yards, but Brady was more efficient. We could throw in playoff stats as well, which would probably help Brady (but hey, why rub it in).
Of course, in the last 3 years since then Mannings numbers went through the roof. It is difficult to imagine Brady having a similar spike in numbers, because he doesn't have the same WR group to throw to and is unlikely to get the chance to throw as much.
Nonetheless, Brady's pure stats at a simlar point in his career are just as impressive. Couple that with his far superior postseason record and it is quite a package.