in your case i would actually say to get the advanced fleet weapons, but if you had MK XII accx2 it would not be worth it.
if they were mk XI accx3 i wouldn't be sure either if it was worth to change it, but since you only lose 1 ACC for atleast 5 times dmg.
i had my turrets changed into advanced fleet turrets since i only had the MK XII borg versions and the fleet versions are definately better for that weapon slot.
I also changed my quantum torpedos, for the same reason.
But i kept my DHC MK XII ACCx2 CritH since those are allready very powerfull weapons.