I was thinking the same thing but lately, there have been some detractors on local radio saying that he may be a little over-rated. They say he runs too upright, and several other negatives. Got me to wondering...
I've seen him play 3 times in person and a bunch on video. The only time I see him running upright is when he is 5 yards behind the secondary and sprinting to the end zone.
Another thing to consider is that he is 6'3" and not 5'11" or 6' tall like many running backs are. He is going to look more "upright" because he is taller than most running backs.