I found the Piranha has very little in firepower, its next to hopeless against fighters heavier than a Manta, even against Mantas I don't find it too useful. It was never designed to be a dogfighter, it's a scout ship.
Since the Panther is used so often in SO, you need to get used to it quickly. Let the gun pool charge between shots, then the cloudburst can join with your chain ions. In fact, the cloudburst is superior to the old tachyons, having the same refire rate, but nearly twice (okay, maybe one and a half times) the damage potential, IIRC.