Yah - not overly impressed either. We'll see over time how he does, but he sure doesn't strike me as an every down back. Not scared of him as a home-run threat either -- not like Gurley or the guys from KC or the Saints great rook.
The Vikings did a really good job of containing him. I've watched him probably 7-8 times this season and he's been getting better as the season has progressed. I think the backs who went after him skews it a bit. Give him another year in the offense before coming to a conclusion. If he can keep developing between the tackles there is still a lot of upside there.