Yeah, I have a Mark X tactical drone arm. It... I was originally like "OMG I now have the gun that Gozer lets drones one shot us with!" *shoots a done* *shields barely move* "Well... back to my Mark XII [Borg] Shotgun"
I have the one with the shield nullifier secondary... and it's been pretty much junk against everything I've tried. Barely drains anything from stronger enemies, and weaker ones don't have enough shields to matter (or none at all if you're on normal difficulty).