To me, stats don't necessarily mean the better career. For example, and as someone mentioned earlier, Taylor Martinez is going to go down in history with the most offensive yards of any Husker quarterback. I can't look up the stats right now, but my guess is he'll also finish with more touchdown passes, a higher completion percentage and more career wins.
But, Frazier won two national titles and was a Heisman finalist. He without question had the better career.
If you take all factors into account, I believe Rozier had the better career, even if he didn't have more touchdowns or yards.