In regards to the emissive armour, I've noticed a HUGE differance. I haven't gone into evaluating in detail I have noticed that when I outfitted my ship fully in Emissive armour, the hits I was taking did significantly less damage. So much so, that I forego shields almost completely. I think I put 10 Kt shield generators all the way around and then fill my armour slots with emissive. Which, by the way, takes some searching to find enough
. Of course, Xiati targets sure make for a nice supply.