Oh God the fast ammo feeder on the Hammerhead is ridiculous. Arm that thing with two heavy machine guns, and anything that gets close to you dies horribly.
And the fortress shield... not sure about how useful it is, but oh man is it pretty. That sound filter gave me a nerdgasm, though I think that at a full 360 coverage, some sound should still get through, but only a little.
Phase ships are... interesting. Definitely a lot harder to use effectively than a normal ship. I'll keep messing around with them, but I've got a feeling I'll be leaving them in the AI's much more capable hands.
EDIT:
I also find it kind of disappointing that like, a third of the ships out there all seem to have the active/normal flare launcher. Granted, these are mostly utility/civilian ships, but it would be nice to see some other type of defensive system for civies, to switch things up a bit.