Gilder, do you mean heavy carronade? I thought I was the only one who couldn't get out of the habit of calling carronades flaks. I blame Unreal Tournament.
Nope. The Heavy Flak used to actually be the best gun for the Goldfish. The gun was really, really overpowered though, so it couldn't last.
Best in the game even, on anything you could slap it onto. Gallon broadsides with the old flak -shudders-.
At any rate, in my experience not much has really changed in its usage for the mostpart. As one of the devs pointed out, balancing for the middleground I've seen most of the spectrum outside of tournaments and there's not much of a change in tactics in the mid-level. Spires of course, have to be blind-sided but are appreciably more squishy, so it comes down to who sees who first, what range and how good the gunners/loadout is. But most seem to be loading the time tested cannnonade + flamethrowers mostly and getting predictably decent results.
Though lacking in killing power, it still stands as a great disabler. Most people seem to prefer ramming for that final "umph" to finish off a weakened airship.