They are the same age and Oden has played 82 more NBA games than Fav has. I dunno... It's easy to guess Oden will never amount to squat, but if the dude can get back to where he was prior to his injury, that's someone who put up Per 36 numbers of 17 points, 13 rebounds, 3.4 blocks and 60% shooting. No chance Fav ever puts up those kind of numbers.
Oden is still months away from being where they want him to be. No guarantee he gets there or even plays a meaningful NBA minute... But I'd still say Oden has infinitely more potential than Fav.