Carolina is a significantly better team overall but what's interesting is that Denver actually wins the matchups despite having more holes on their roster. Carolina's few weakness play into Denver's strengths and vice-versa.
I think Cam is going to struggle very, very badly. He is a different QB when pressured, and his pass catchers will likely be dominated by Denver's secondary. Denver's defense isn't just good, it's 2013 Seattle good. And we all remember what Cam did against that defense: Jack squat. With all due respect to the 2015 Hawks D, their Sta-Puff The Marshmallow Man Soft zones were never going to throw a QB like Newton off his game. And Arizona's defense was over-rated all season long. Denver's defense is a different breed, they will give Newton problems.
Denver's run D is also elite which means that Jonathan Stewart is unlikely to be a factor.
The key for Denver is drawing up a smart game plan that uses huge mismatches to their favor, basically targeting whoever among Thomas or Sanders that isn't being covered by Norman and trying to avoid turnovers. Carolina will probably need cheap points to win this game. So being mistake free will be huge for Denver.
Carolina's best hope is to force Manning into mistakes like they did for Wilson and Palmer. Which is certainly possible if Manning is not careful. But it's almost impossible to imagine a scenario where Manning plays well and loses. Carolina has to make Manning a liability to win. They have to. We've seen Manning have some terrible games in 2015 so building a gameplan around preventing mistakes is key for Denver.
Ultimately I think this game will be decided by mistakes. And I think Cam will be in a tougher position to avoid mistakes than Manning will. And history shows that top defenses typically beat top offenses in the postseason. So I lean a bit towards Denver as an 'upset' pick.