If you think you are ahead, get it in on the flop. His range could be so many different draws so on the turn, how are you going to know what a safe card is? Also, how do you know your opponent would bet a blank card? If he really is drawing and is in position, wouldnt it make sense for him to check behind on a blank? By checking you are giving him another chance to hit his draw and I just cant imagine you are going to be able to safely c/r the turn often at all.