defense and home field, in my mind Broncos have to be favored. NE hasn’t been that strong all season, will get healthier but don’t see them winning on road. Chiefs match up well with everyone, I live in KC, my fear is, the win streak has been against bad teams. Broncos game at Denver was when Manning couldn’t even throw a pass. I would say Broncos vs Cards (tough not to roll with Panthers) in Super Bowl, Cards win.
Considering history and percentages, I would say that you are correct. From 1990 to 2012, 9 of the champions were #1 seeds.
http://www.nfl.com/superbowlchamps/seeding