I recently switched over it's loadout to 2x Heavy Autocannons and 2x Anhillator Rocket Launchers to try to mix anti-shield and anti-armor.
Yeah, that feels like it'd probably be a bit clumsy to use as a primary vessel, though it'd be okayish as fire-support for other ships.
Then again, my takes tend towards not relying on missiles at all; a hammerhead with a pair of railguns (forward turrets), a pair of vulcans (rear turrets), an arbalest, and a heavy mortar, is pretty solid. Insulated Engines, ITU if you've got it, max vents, at least 8 capacitors, season to taste with other hull mods or maybe harpoons (for AI use) or sabots (if you're going to be flying the ship yourself). The hard part, there, is finding that pair of railguns; you can substitute light needlers, but those are pretty rare too.
For a design that doesn't rely on rare weapons, I'd try 2x arbalest, 2x light assault gun, 2x vulcan; it won't have quite as much anti-armor punch, but it'll fare better against (unshielded) enemy fighters.
Or, if you do have all the rare things, 1x HVD, 1x Heavy Mauler, 2x railgun, 2x vulcan, ITU, is a very solid build for AI use. Maybe a bit slow to kill stuff for player use, but the stand-off engagement range dramatically improves survivability.