Collectors - Barriers.
Mercs - Shields AND Barriers.
For any one who using biotics, Shockwave is good for Collector-related missions. One-shots Husks sometimes.
Depends on which mercs you're dealing with. Eclipse and Blue Suns usually have barriers and shields, Bloodpack usually only have armor (besides the subboss characters).
Now that I think about it, Zaeed is definitely the way to go. He's got concussive shot to deal with barriers, incendiary grenade for armor, and disruptor ammo for shields. Or you could just give him the Geth pulse rifle for shields, his damage output is high enough that it really wont debuff against organics.
Geth Pulse Rifle is fucking tits. Throw a maxed out Shredder-, Warp-, Incendiary-, or AP-ammo on it and it will chew through shields and, very quickly, chew through whatever is under it. Works especially well with Adrenaline Rush. No muzzle climb on an already accurate as fuck weapon. lol.
Speaking of Shields, I need to try playing Mass Effect 2 as a Sentinel. It's the only class I haven't touched. I started the game initially as an Engineer before I realized within minutes that the class is useless. Combat Drone to force enemies out of cover? THE ENEMIES ARE NEVER IN COVER! Still finished the game, though.
Finished the game last week as a FemShep Soldier.
Finished the game as a BroShep Engineer (and never used Combat Drone).
Finished the game as a BroShep Vanguard. This class is fucking fun. lol.
Sentinel is derp after you get Assault Rifles. Biotics + Engineering + Additional Shields that can be refreshed infinitely and remain effective until you are shot too much? I didn't even want to play through the whole initial mission. I can see how the theory of the class would work.
Shield during non-combat, ammo power (in this case, AP-ammo), run to cover, shoot shoot shoot, shield refresh automatically, shoot shoot shoot, run to next cover, rinse, repeat. What's worse is that if you are low on super-shield, you can manually refresh it for a delay in using other powers, but really, you're not an Adept so how much power usage are you expecting here?
Outside of Insanity and maybe Hardcore, you can't die as a Sentinel.
I was a total Firefox addict until I started using Safari. Mostly started using Chrome because it took up less screen space on my netbook, but I've not even booted up that computer for months. Planning to sell a bunch of stuff (Macbook Pro included) and get a 13" Air when they refresh the line this year. Or maybe a 15", if the rumours are true...