I would just like to restate that any sort of asset in the uber-high-cost category is very difficult to make interesting. Powerful is easy, interesting is hard. You really only need one Krogoth-class unit, and for a unit of that class, fielding it should be pretty decisive. Tech 1 is where the rubber meets the road in TA style games. Tech 2 is the garnish on the army most of the time. And "Uber Tech" should basically be more significant for putting pressure on players by the possibility it could be constructed than by actually making one.
I would think that engines capable of moving asteroids and planets would fall under this class of technology.
Don't overuse this whole Uber-X thing. Uber cannon is good, but if you add in Uber-tech, Uber-asteroids, Uber-nukes and Uber-cookies it starts to get boring.
