These seem to drop a lot less since 1.4 than they did prior. I always have my smuggler companion risha with plus crit to slicing running the mission for these. She gets them way less than before. Also on my inquisitor I always have andronikus whatever his name is with like +5 crit to slicing and he gets these like 1 out of every 5 missions now?! That's crap ratio for 2 companions that are supposed to have a plus chance to get them!
1 out of 5 is still a 20% success rate, id say thats pretty good still