Stacy is a guy who picks up the blitz, has relatively shifty feet and has the power to break a chest tackle. He doesn't have NFL breakaway speed and is very suspectible to being tripped up when players get his feet.
Running behind Dallas's OL will help him a lot with the latter issue.
He isn't golden but he is proven and has a lot of the same attributes that Demarco Murray had and he is only 24.
Although Stacy runs in a style that takes a lot of hits, his collegiate and pro workload suggests he has another 5 years in him.
He is a cheap contract.
I think a Stacy/Darren McFadden thunder and lightning rushing duo could be as effective as Murray. I still want Zack Zenner behind them though. (Draft Zenner.)