Well, Allods is supposed to be very cash shop dependant. ( I don't know if that's changed.) Can't say what I think of PvE on Allods since I never played.
And RoM is only cash shop dependant when it comes to PvP BUT I've heard that you can use in game money to purchase cash points. (Correct me if I'm wrong.) PvE is decent. And the PvE world seemed pretty big to me on RoM, for a F2P game that is.
You should try em both out and see which one suits you best.