Flak is much better for wormhole-bunching since they do AE damage and that's typically where things will more often be bunched up. I could see using a few to protect stuff under FFs from vampires/cutlasses/shredders if they can actually reach now though.
A few missile, basic or sniper turrets are better for "a few blibs" rather than something that is at its best when fighting a couple thousand things at once.