Returning armada, aside from being a nifty ability, can be used to generate wads of cash via reclamation or just nuisance value. The primary problem is that this cash is not affected by fleet maintenance. Ok fine, TEC also gets free nuisance units which don't apply to their fleet count via the rebels, and the pervasive economy to reclaim the bucks. Advent gets.....5-10% additional faction, which, while it does affect economy, is still affected by fleet maintenance, and the only source of free units is the level 6 ability of one of their capital ships.
All the 3 factions have 2 'super abilities', or Tier 8 non-superweapon technologies.
The TEC has Insurgency and Pervasive Economy. Insurgency isn't amazingly useful since it can be blocked by culture, and the Rebels attack the TEC as well(this is just stupid). Pervasive Economy does let them effectively print cash and therefore not have to worry at all about economy.
The Vasari has Returning Armada and Highly Attuned Sensors. RA is well known enough. Highly Attuned Sensors give the Vasari vision of all ships traveling through phase space, which is useful for tracking enemy fleet movements, but still requires you to send scouts to check on their gravity wells.
The Advent have Allure of the Unity and Mass Transcendence. Allure of the Unity gives them +10% allegiance, which obviously helps economy, and Mass Transcendence auto-levels every new capital ship they make to Level 4, and doubles the rate at which they gain experience.
