Powerful or not, I get so salty when someone wearing a full set of three slot gear kills me. Mostly when said three slots are three damage ups, three ink tank ups, and then some extra ink charge when in squid mixed with more ink tank up.
This is IV breeding in Pokemon all over again.
Kind of, but with diminishing returns on stacking abilities I'm not so sure those people are better off than those with 12 separate abilities. I think certain abilities may stack more effectively than others, but dedicating entire pieces of gear to a single ability seems like a terrible idea.