Take it with a grain of salt.
Watch a game like this.
Yes he does get stopped at the LOS early on but he gets better and better.
what I see in this is if he has a hole or crack, he gets good yds,but if there is nothing there, or a dl grabs you in backfield, any rb is going down.
The main thing many here dont see , is that D got a lot of carries in college, quite a few pass targets, so he had better chance of chunk play or long run.
With cowboys, he will be used sparingly and so will have way less chance to break off chunk play or long run.
Cowboys have pollard on FT so jerry will want him getting most carries, and RJ probably # 2 so theres not enough left for dv.
What I would do , is the first team we play with weak run defense, I would make DV the feature back , give him 25 carrys, 10 passes,
and see what he does with it.( I would change the way our OL blocks too.)
He does have some good moves, and is elusive in space/. But he needs to be utilized properly, not just in a few plays a game.