Provoke Hysteria is the best siege attack out there. Besides, by the time you get it, you will be using it against hard to crack planets.
Though the Vulkoras is the best due to SS and DSP. Sure, RP on the Marza is good instant damage, but being able to septuple your bombing abilities is pretty dang good (and that is before your incredible passive..)
I'll post/edit this post later...
But at least now the Antorak does something. And the fact that it was my idea makes me even happier! But POH is as it stands an okay interrupt. Its the others.. But really, the Antorak is a special use ship. Sure POH has obvious uses, but unless you use a Kostura to go attack the enemy deep in their territory on a large map, its not going to be worth a whole lot. This is why the Vasari ships behave the way they do. And this is also a strategy that few use... Use the Kostura to get anywhere at any time and your Antorak for all your assorted needs..
POH: Just in case you encounter a Marza or the like sent to kill you, you can stop it.
Speed Boost: Decrease Transit time when moving through enemy Grav Wells.
Subversion: Prevent the enemy from creating any local defenses against you.
SPS: Just in case things get a little too intense, you can always leave.
That is also why the Vulkoras IMO is has DSP. It allows it to work in tandem with an Antorak to clear planets. The same goes with DP on the Egg. It also helps scoop up planets. Just as the Advent have their Holy Trinity, the TEC have the GRG+FF combo, and the Vasari have a guerilla squad. Its just that no one ever thinks about it..