I've been wondering this lately... I mean before S7, full plasma resist was the way to go, but after S7, has something changed or am I simply crazy? I hardly see my plasma resist making any kind of differance... Do the borg use any other kind of damage?
Kinetic for torpedoes is an obvious thought, but what should I put armour into?
There's a possible bug that the Devs say they're looking into, where powerful Borg NPCs like the Gates and Tactical Cubes are doing more damage than they should. Plus, invisible Borg torpedoes have been one-hit-killing players for quite some time now.
Honestly the #1 damage type to look out for from the Borg is kinetic. Even an ordinary garden variety sphere's torpedo does around 20K damage. The torpedoes from gates and tactical cubes does over 40K. (The "heavy"/high yield one does far, far more)
So, plasma resistance is nice and all especially with the way every borg shot seems to set you on fire now, but what they generally kill you with more than anything else is their stupidly powerful torpedoes.
As far as disruptors, the assimilated klingon ships use disruptors. This includes all the ships on Cure Space. Also Donatra.
the blue beams are not tetryons, those are tachyon beams. they drain shields too. then there is plasma weapons ofcourse and an insane amount kinetic dmg. they also have a trillion other shield drain abilities, which hazard emitter or tacteam 1 can already clear.