My choise is the Falcon. This weapon is like SE Decoy on Geth. They can't move because of the stagger. The weapon's role is pure support. You won't kill alot of enemies, but you will keep them at bay, while your team is dealing with boss/es. On gold, ammo mods are not MUST, but pretty close. Disruptor and cryo are best for this weapon in my opinion.
If you have 2 or more biotics in your team, you can try drell adept or the justicar with falcon. You won't have 200% CD, but your teammates are the nuke squad. You can complement them with reave and clusters, and keep at bay any smaller enemy, even stagger the big ones with the falcon.
(Btw justicar's reave don't wrwrwrwr your teammates. It wrwrwrw your ears, but not their's. Drell's however is wrwrwr dubstep with the nuke squad explosions

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