Actually, this talk about combat reminds me that we only saw the on-screen dice roll for non-combat things like persuading the guard to open the door, or trying to feed on your companion. They of course do the dice rolls in combat, but those are only shown in the combat log, probably to keep things moving at a brisk pace.
I only particularly care about seeing both rolls in the non-combat instances which normally show the dice rolls anyway. If you want to see them all the time in combat, that's fine, but personally, I think seeing the rolls all the time (other than what the detailed combat log does) might slow things down a bit, so I'm more concerned about seeing them in non-combat.