I've read several different build threads about escorts and cruisers. A lot of them recommend turrets for the rear. I decided to attach a couple turrets 90 damage and above to my Galaxy Dreadnought and Prometheus escort. I did make sure they were the same type as my beam arrays/banks/cannons. I wasn't impressed by their performance compared to beam arrays. I normally run two beam arrays and a torpedo in the rear, three on the dreadnought. The only benefit I can see them provide is that they act as extra forward facing weapons.