I am playing with a battleship/cruiser, in both cases I deal more damage with HE rounds. It sreds their modules, leave them incapacitated, makes them unable to use rudder and go left or right and it just eats their hull (4k shots on t3 ships)
Whereas shooting with ap and hitting side hull, deck and guns barely makes 1000 dmg shots. I don't know why is that but I feel like I consistently do more dmg with HE rounds