On the whole spirecraft versus golems thing:
1. I think that people need to not freak out too much. People seem to act like we never change our minds based on testing feedback. I don't know where they get this idea. If something is massively broken, we'll change it.
2. If golems are underpowered, I haven't really heard much about that (aside from the cursed golem, mainly). Going back to the old AIP-granting methods isn't something I'm contemplating, as that seemed to be hated by 70% of players or more in my non-scientific polling. Players are too conservative to risk that much for a golem.
3. I'm open to making further changes to the golems (not this week, but next and after), but I want to keep them distinct from the spirecraft. For those complaining about them without even having used them lately -- please use them before you complain.
4. As a number of people have pointed out, having the spirecraft be finite is pretty interesting, largely because it encourages a different kind of play. The tendency to want all ships to follow the same pattern (aka, I can build them and retreat them, or build them and replace them) isn't good. This adds a third avenue of build them and use them once (maybe twice).
5. As to the worry about having to commonly lose them and rebuild them: that's only even going to be possible with the weakest of the spirecraft, as the stronger spirecraft come from the rarest asteroids. You'll miss them when they die. They will be rare. And most of the more common ones are useful, but nowhere near golem-level. They're a bit bigger than starships, but single-use.
6. Yes, these are humans-only. For now. I imagine that some of the AI waves in the fallen spire that use these will also use the spirecraft. And I imagine there will be a special AI type for spirecraft, too. But, in general: like golems, mostly they are human-only.
7. As to concerns about this making the game too easy again, I do share those concerns. Mostly because this is only in an expansion, and if it's balance well WITH these that means that it's too hard without them, and vice-versa. I haven't solved this one yet. Possibly the combination of time cost + material cost will make it all work out, but that remains to be seen in practice. Possibly the act of building a spirecraft needs to stir up the AI some (making some waves against that planet, etc), but once they are built they are AI-stir-free. That would make them riskier to get, which is great and more interesting anyway, but then just as useful as a trump card once you have them.
8. My last point for now... The games of AI War are so long that this tends to make people strategically conservative, which I sort of already touched on, but which is also super important to think about. Golems giving off AIP scared the bejeebs out of a lot of people, to the point they never decided it was worth the risk to use them. This made them sit there stagnant except for those players that wanted to run around with a big ship (the recent changes have fixed that, but made them less attractive in the process -- they probably do need a buff, but that has nothing to do with spirecraft). In the case of spirecraft, people just hear "I only get to use it once" and sort of freak out. Folks are used to being able to continuously repair or rebuild ships, which keeps the opportunity cost of an attack limited to "how much time do I want to spend rebuilding this if my attack fails?" Here we now have the "is this worth using my spirecraft up for?" opportunity cost, which adds a new element. If you don't like it, you're not forced to use it. But I think this game is really going to hit a wall where it can't grow much more if we don't experiment around with different types of strategic mechanics (not just tactical mechanics), and this is my most recent attempt to push the boundaries of the game outwards.