I think it's the sox but it's very close, imo. I think the sox have a better starting staff because of the bottom 3, I think silva is going to be far worse then last year, Lohse sucks and Mullholland or Mays aren't good either. I think the sox have more depth to their pen, even though I'd say the twins have more dominating guys at the backend of their bullpen. I think it's very close but I think the sox have the advantage right now, jmo.
EDIT: Looks like I read the question wrong and it's just the rotation, not including the pen, if that is the question I definitely think the sox have a stronger rotation.