To me, the best RBs in the pros have that downhill running style. You see it from Starks, Freddie, Jamaal Charles, etc.. These guys get the ball and don't try to juke your socks off. They hit the seam hard, make one cut at most and always seem to fall forward for that extra yard.
As for Spiller, he claims to have learned this lesson late in the season. We'll see, hopefully for us Bills fans he has.