Okay, looks like we have a clear leader at this point. From the next release:
* Siege Starships renamed to Antimatter Starships for the sake of clarity, and given the following new description text:
** This starship is the best capital killer in your basic fleet: excellent against starships, guard posts, guardians, most turrets, and other large ships like golems or spirecraft. It is so specialized that it can't even fire upon most small mobile targets. That said, many targets (forcefields, most fortresses and command stations, etc) are specifically protected against the Siege's antimatter bombs.