I wouldn't want to see cloaking to the point of invisibility but being able to reduce enemy detection range via sensors with cloaking sounds interesting - but there's no point unless your enemies are using a lot of sensing tech to do serious tracking of you and others in the first place.

GalCiv1 had terror stars that could destroy planets. Personally I don't care for the idea since I think these types of games are about building an empire, not reducing the galaxy to vapor - but I can see how that might appeal the the darth vader in some of us. The word is that they didn't initially include this type of thing because the AI has trouble dealing with it well, which results in players cheesing the AI. Cheese is good on pizzas and burgers, not in games!

(I would also guess that the AI would have problems dealing with cloaking tech too, resulting in an unbalanced advantage for players.)