I will second Babaluga's comments and add a few of my own.
In coop when it's not your turn you can't see how many AP you will have next turn for planning, so seeing this would be nice.
You can't switch to the inventory of another controlled character, meaning you can't check out potions, arrows, etc for your next turn.
It leads you the player who is not in control sitting with nothing to do before their turn.
