Quick reading often leads to mistaken interpretations, my fault.
Anyway, what you state means that you get 8 more income merely based on culture and induced reverence. For a planet with a base income of 20. But on Faster an upgraded Terran is not 20, but sensibly more. Given that upgrading Terran habitability is always one of the first things to do, as it costs little and improves your income stably, I guess the number you propose should be recalculated.
Besides, the increase applies to both metal, crystal and money extraction.
It allows you to make some utility starbase, saving module space if you have little, etc.
As with every move, there is no absolute useless or useful solution: they work or not based on circumstances. And I have to say, that for me until now, when I did it, it worked well.
Quoting 137, reply 10Consider that Capital has a bonus to income as well.
This is an entirely additive income bonus that is not affected by the allegiance multiplier...
Quoting 137, reply 10This upgrade is not to be built in a frontline world:
Which implies your SB was built only for economic reasons...in that case, you need to now take into account the cost of building the SB constructor and deploying the SB, which more than doubles the total investment...
You could argue that some of that upfront capital is also being paid off by trade port upgrades or auxilliary government (which is only "economical" if novaliths are around)....
I'll reiterate my original statement that this upgrade is really only useful if you are in very very long games (which in most cases are only long because the player is choosing to drag them out)....
In your capital, you need a starbase. Advent Starbase is interesting in the fact that it can be used as an utility starbase. While the price is hefty, in the proper place it works. That a starbase is hefty is quite a sure thing: but with a fighter module it keeps away rebels, with the appropriate race specific module, protects from planet loss, and it can give you culture boosts free of logistic costs, trade and allegiance bonus.
So, if you pick the right planet, the cost is worth it.
That the bonus for the capital was applied after, I personally suspected it, yet this doesn't reduce the effectiveness of the move, in medium length games.