For tanking purposes, the dyson regenerative shield is also a really good choice. I have it on almost half of my ships, and i must say that it performs most of the times better than my maco used in 3 of my toons lol. But all depends on your build and your playstyle.
It may also depend on what you're taking. The changes to the Aegis Set with the 1 second immunity to damage is very effective to deal with a planet killer or the crystylline entity, for example, but not so helpful when you need to hold off a large number of attacks.
Maco. Its stated decently and you get power for being shot, and your boffs have a 5% reduction to cooldown.
8472 Set is gimmicky.
Everything gets a 5% cool down reduction with the two piece. Even weapon cycles.
"Cheat wherever you can. A.I.s are handicapped. They need to cheat from time to time if they're going to close the gap... Never get caught cheating. Nothing ruins the illusion of a good A.I. like seeing how they're cheating."
— Jonny Ebert, lead designer of Dawn of War 2 on video game A.I.