Obviously I watched him a lot as a Longhorns fan so here are some quick thoughts...
He's an outstanding receiving back. He's so good as a receiver that he can make a career out of that even if he's average as an actual runner because we've seen elite receiving backs before do exactly that.
As for an actual backfield RB? He's decent at best. He's got great speed and acceleration so if we create some space he can take it to the house.
But his agility is decent at best, his vision isn't very good, and he doesn't break tackles very often.
I like the pick for where we got him and he'll definitely help the offense, but he's nowhere near good enough to be a lead NFL runner.