I don't think experience is the key variable when evaluating college running backs. I watched every game Fournette played last year, and I don't think he's as good as Dixon. Speaking of athleticism, there is a video of Dixon doing a 360dunk (at 5'10). Granted Fournette has faster top end speed, I doubt he can do that.
I make comparisons between the two because I think Dixon deserves more media attention in north Louisiana than Fournette does. Like I've said before, LSU intends to promote the assumption that they have the best players in the state. They like to leverage north la recruits with that assumption. If it is exposed as untrue (in certain positions), it could hurt their strangle hold.