One advantage we have against UNC is that a few of their main weaknesses really feed into our strengths.
For one, they have a tendency (although they've been a little better lately) to sometimes be loose with the basketball. If they do that against us and it creates transition offense, then it severely diminishes their chances.
Two, Roy doesn't zone, and he's pretty tried and true to how he's going to defend. This year's UNC team isn't bad defensively, but they lack really good individual defenders. Their best individual defender is Kenny Williams, who is going to be giving up three to four inches (minimum) to whoever he guards, and that doesn't factor in length.
UNC is going to try and run because that's what they do. They're also going to rebound. If they can win the latter and make outside shots, expect two really close games.