Is Rory a better 'athlete'... Yes
Is he bigger and stronger than Penn... Yes
Sometimes a younger fighter has everything won on paper, but I really think the Prodigy has that X factor to win this. BJ is so well rounded, has the experience and has been through the battles.
Penn's biggest enemy isn't Rory, it's himself. If he can dig deep and survive the Mac truck coming at him, this fight is very winnable. Penn can't get caught on the cage, he'll get worn down, swept and GnP'd out.
If he tags Rory standing, keeps him at bay and doesn't get taken down he'll win this fight.
Penn via UD. I need to see him lick those gloves like a cat (Sanchez fight)