Official SE:IV Gold Patch 2 thread...

[Baron Munchausen]

Emissive Armor is a delicate balance problem. If it is too powerful it will make you essentially immune to direct-fire weapons. If it is not powerful enough it is just expensive armor. The thing that makes balancing so tricky compared to SE III is mounts. Now you can multiply the damage of a given direct-fire weapon by 3, 4, or 5 times! Ideally, a given Emissive Armor needs to reduce the damage of weapons that are available at the same tech level but not completely cancel them. Figuring out how to balance research costs so roughly equivalent levels of EA are available for comparable research costs to the weapons is the trick. You have to factor in the changes that mounts cause, which is much tricker than the SE III system.