Armor:
Armor in MP works differently to SP. It only reduces damage and does NOT protect against Headshots.
Maximum Nanosuit significantly reduces damage taken and protects against Headshots.
Airstomp will not kill ANYTHING if you use it on the same level. It seems to kill you need to have a higher point of take off than your target. How high, I dunno.
Stealth:
Getting shot while in stealth, you take considerably more damage. Back shots appear to be near 1 shots.
Breaking stealth from firing, the first shot, will have horrible accuracy(to the point that you will miss unless you're literally on top of your target, also your cross-hairs will disapear for a few seconds after breaking stealth in this way.
Maximum Stealth will not hide you from enemy radar.
[bug?]Sometimes due to lag or some weird bug. Enemies coming out of stealth from shooting do not always de-cloak on your screen even though the kill cam and their team mates see them out of stealth. (I think this is a bug as it just happens intermittently)
[bug?]Sometimes when activating stealth your gun is still visible.
Power:
Any questions or finding that are against what we've discovered so far? All of this was discovered on dedicated servers from testing.