DS was used in a non-typical RB way more than you probably remember. HIm and PT lined up in the backfield together, creating mis-matches, people don't know who the heck is doing what. A lot of our best offenses have been based on mismatches. Kamara and Harris line up in the backfield together, who are you going to sell out to stop?
I do think Harris has to be used more in screens and Texas concepts. Also, I like to see him in more open middle field match ups. Unless it's a curl route or a comeback... I really don't want Harris being pinned to the sideline.