a) No, it's not (at least not with my playstyle), since you don't usually have enough ability points while fighting in higher zones to waste them on such utility. I probably use it no more than 3 times a month on my 4 star Straxus, every other time he's just a big moving shield for more important bots.
b) It's situational, when a proper squad is supposed to win 100% battles in proper zone with any layout, unless countered by multiple bugs. It also becomes less and less possible as a battle goes on.
c) Honeycomb layouts never worked in the first place, any competent squad destroys them with ease. It might actually be one of the worst ways of building a base.