Spiller is a dynamic player, but my rule #1 in fantasy football is to avoid bad offenses like the plague, when it comes to drafting your starters. I got Sam Bradford for $5 in my big money keeper league, but other than that I won't touch the Bills, Seahawks, Browns, Bucs, and Rams.
My running backs in my one league are Ryan Matthews and Jonathan Stewart, and in the other league they're Ray Rice and Shonn Greene.