I think armor lock is a good armor ability that may be slightly overpowered in traditional Reach, and slightly underpowered in TU setting. I mean having it drain when shot is a good idea, but it drains too quickly IMO in TU settings, but honestly all the armor abilities have balancing issues that I'd change.
Sprint is fair but I think everyone should be able to use it, and have a second armor ability, because as it is sprint is just used to get to the power weapons or vehicles first, and it is rarely used for it's original purpose, to flee or get into combat more quickly to help allies.
Camo doesn't need a reduced battery, it needs to keep players from aiming down sights. Cloaked snipers are the biggest problem with that armor ability so an easy fix is just to keep players from looking down the gun's scope, it kinda makes sense since it IS invisible, right?
Armor lock; well just see above.
Hologram is really underpowered IMO, it should show a red name over the head, because right now it's just a dead give away as to a holograms presense when it runs towards you without a red name, and I think it should also show up as a red, and not a white dot on the motion sensor as that is still a big tell (should still appear white on teammate motion sensors though) Since these changes would improve the holograms functionality I think its recharge time should be increased to maybe 12 seconds, from 7, and keep in mind, it still runs straight forward, it still doesn't cast a shawdow, it still flickers when shot so I think this just makes it good, without being OP.
Then there's jetpack, which I'd argue is fair, but alot of so called "pros" argue it ruins map balance, so I say jetpacking should cause max bloom for all weapons but otherwise keep it as is.
Evade is great on elites but Spartans evade too far in one go, so I'd knock their evade distance down to elite levels. Would certainly help in infection when zombies can't do 50 foot evades at 100 mph.
And drop shield is good, but I wish plasma weapons destroyed it about twice as fast, vehicle plasma weapons aren't included in this damage increase though, because that way you might then have a reason to pick up a plasma weapon in spartan BTB, as currently the long range engagements leave their slow moving shots almost useless.
Jeez that was longer than I thought, well that's my rant on how armor abilities should be fixed........ I'm done.
[Edited on 01.23.2012 4:59 PM PST]