Here's my optimistic take on the game...
This feels more like an NBA Game 7 than a Super Bowl, which is more of an NFL trend. It's hard to imagine either team, with this amount of preparation and focus, getting blown out. The teams were almost neck and neck for point differential this year with very similar offensive output and defensive points allowed.
With the exception of two flukey Denver teams (one flukey because their offense played so poorly, one because their defense played so great), virtually every Super Bowl in the last fifteen years has been competitive, almost all of them decided in the fourth quarter with lead changes or at least genuine suspense. Is Kansas City an exception to the rule at 14-1, and will they destroy Tampa Bay? I don't believe they will. There have been many blowouts in conference championship games during the fifteen year period. There have been teams objectively better than Kansas City who were unable to blowout opponents objectively inferior to Tampa Bay.
So, I think this game is going to be very close. You also have two quarterbacks that are unlikely to be on the wrong end of a lopsided defeat, as both of them will score points quickly as soon as a defense loosens up at all.
I expect this game to be competitive into the fourth quarter, and that's why I give Tampa Bay the edge. Some of it may come down to luck/clock, but I like two things about that scenario:
First, the Chiefs offensive line is a lot more likely to wane down as the game goes along and the Chiefs run out of novel plays; Tampa's defense is likely to have figured out most of what's being employed by then.
Second, I think the Chiefs are a better coached team. Later in games, I think it comes down much more to execution and players than it does coaches. Teams have already run 50 plays. Defenses know their limitations and strengths. I think Tampa Bay is a better overall team, player for player.
I'm not going to confidently pick Tampa Bay because I'm still hesitant to pick a team that still seems a bit sloppy and a work in progress over a well oiled machine. But I do like the overall likelihood of this game being close and competitive, which doesn't give Kansas City a chance to be at their best (especially their defense) as when they're protecting a lead.