For a Vehicle, it is Hardened Armor. Why you may ask?
A Vehicle only suffers the +1 to PSR hits, it will not be slower. Then there is the added benefit that any critical hit rolls will suffer a -2 penalty. Even if you don't use more hardened than standard armor, the effect is there. If I use 240 Points of normal armor or only 120 Points of hardened (weight is the same) the bonus is there. Combine that with an armored motive system and vehicle get VERY VERY survivable. The +1 to PSR affects a Vehicle not that much. And I'm not sure, the re lasers will be so good. They weight so much more and produce enormous heat. I think I would use 5 standard med Lasers than 2 Reengineered ones and would have more of it.
For every other unit it is Ferro Lamellor.
Well, I am tempted to test out the new anti ballisitc armor with a blue shield project. This combo should renders almost any headchopper weapon obsolete.