NFL Wk2 Defenses - BAL vs. CIN or OAK vs. STL?

This is kind of tough for me. Should I pick a good Baltimore's defense vs. a talented/experienced Cincinnati offense or a middle-of-the-road Oakland defense (featuring one of the best CB's in the league) vs. a crappy St. Louis offense with a rookie QB? I feel the OAK / STL match-up has a lot of potential for sacks/picks because of the rookie QB aspect