Griffin has looked shaky for the last 16 months. Roethlisberger is on fire. Go with the hot hand at home. Big Ben seems a pretty solid choice.
I would start RG3 over Roethlisberger, RG3 plays Jaguars and Roethlisberger plays Baltimore. Baltimore's D is a little better then Jaguars. I see RG3 getting more points so go with him.