I am really enjoying them because they actually feel like an evil alien faction that came to destroy everything. Other "evil" factions are usually pirate like, that even form teams and you can even side with them. Dark spire is all over and attacks everything that moves, no matter their alignment. I am really liking how they indeed seem like "pure evil". I am playing on 0.65.2a currently, since I wanted to at least play once a game with as many faction as Nexerelin could hold (I managed to get 24). Their number lowers in 0.7? I hope that is editable, because I would definitely raise it to the number it is on the current game, at least for a couple of plays. Definitely loving the inhospitable (to everyone) galaxy feel.
Actually I am finding it really cool looking, but I guess that is a personal view. My jaw dropped when I saw it classified as a destroyer. I am scared to see how strong the Cruisers and the Capital is.. Oh and as for designs, the only one that looks weird to me is the Amethyst. I would say the Feldspar too, but that one not so much. The reason I say the Amethyst look weird, is because it look more like an actual "human" designed craft, rather than feel like the rest of them. But I do not find it bad, I can make a lot of scenarios in my head why the shape is like that XD But definitely the Spire ships are my kind of ships.