I use the Breen weapon (CRM) just the first attack on it, not the aoe. It fires very fast and seems to do decent damage against them.The slow and sometimes freezing it does also helps when there chasing ya. Also I seem to have more luck with polaron weapons that anything else. For some reason polaron seems to take there life down faster than other weapons for me, although I thought they had resists to it. Usually go for the duel polaron pistols if not using crm weapon.
Since you only really encounter these in Cure, you probably want to be using a sniper rifle to pick them off at range.
As mentioned, the Breen weapon is nice. For small groups I tend to also use a stun pistol - the stun means they slump over instead of rushing at you, giving you or your team time to kill them.
Elite Tactical Drones:
I have a sci officer (BO) with the 'Dylovene' buff. Get that applied on you, get your melee on and get in there! If you then position the elite so its back is facing the rest of your team (players or BOs) then the elite goes down fast. The dylovene buff massively reduces incoming melee damage to the point where you can probably handle two elite tacs at once - provided neither is flanking you.
And as with all fights, expose followed by exploit, plus flanking damage. These work just as well on Borg as they do on anything else.