Well, you cannot armor lock in mid air, but if you do it at the impact of a fall it reduces the fall damage. Also if you are on someones head and you armor lock you will both be killed, sending both bodies flying into the air.
When I have tried to do the "engage" armor lock without actually going into lockdown the camera zooms out and it starts sending me into lockdown anyways and I cannot shoot for a moment. Is this supposed to happen or is LB just sticking on my controller?
One thing that really pisses me off is people Armor-Locking in CTF around their flags so they can reset them without worrying too much about dying. I guess I'd do the same thing, but it's a dirty move.
Eh, you could just use all stalkers/scouts and either go stealth and wait just outside the emp range and/or run in from afar to get assassination/grenade kills. It's not the be all end all here; everything can be countered by something else.