Short answer: No difference.

Longer answer: Back when we had accuracy, there used to be a penalty to your accuracy for attacking from the front (or a bonus from attacking from flank/rear, depending on how you look at it). It is theoretically possible that they maintained this sort of penalty/bonus system for Direct Hit, but I cannot find any official word on it, nor any extensive player research, that would indicate one way or the other. I would gladly welcome any evidence that proves it more concretely one way or the other.