The one thing thats bothered me about playing this game for so long is that no matter what when you are in the Offensive position you ALWAYS have something to do this is building your fleet, expanding, and keeping your Eco player safe. When you are in the Suicide position its about protecting your self. Starbasing your territories and making sure you dont get owned to early on and become a annoyance for your opponents. But Economy has always lacked for me, you expand and build Trade Ports and thats it for the most part. Its not that I have a problem with the Economic position itself, its more of the fact that if you play TEC EVERY single Tier has an upgrade that you can get it gives you something to focus on while they are expanding this in itself isn't a huge problem, its comes down to that the other players are for the most part just rushing to build trade ports with not much tech options to keep them busy while they wait.

For Example, this is how my Economy Tech Tree is when I play the TEC.(Excluding Shared Resource techs like High Density Zoning)

Tier 1: Modular Architecture, 
Tier 2: Expedited Permits 2/2, Advanced Civic Design
Tier 3: Rapid Development
Tier 4: Huge Cargo Holds
Tier 5: X
Tier 6: Immense Cargo Holds, Development Mandate 
Tier 7: X
Tier 8: Pervasive Economy
(It should be kept in mind that Truce Amongst Rogues is a HUGE economic option)

Pretty much every single Tier except for 5 or 7 has something you can do to improve the game play of the Economy Position this doesn't necessarily have to be increase to credit gain.  Here is the Tier Trees for the Advent.

Tier 1: X
Tier 2: Communal Labor(Kind of Lack Luster for its early game cost)
Tier 3: Mass Communion (Rebel Only)
Tier 4: Assimilated Populace (Loyalist Only)
Tier 5: Expulsion (Rebel Only)
Tier 6: x
Tier 7: x
Tier 8: Allure of the Unity

There isn't really a lot of room to have a progressive upward build of your economy through the Tech Tree like the TEC have. This makes very slow, repetitive gameplay for the Advent and I think its time the Tech Trees had a little bit of change for awhile as a lot of the Upgrades in there don't seem like they are worth the cost of them. Like Resource focusing. So if stardock would will it I have some recommendations to help improve the gameplay of the Advent Eco player merely by redistributing the Research tree a little bit. 

Tier 1: Move Communal Labor to tier 1, this will give them an early game option to build their structures faster, and it doesn't start out to ridiculous as the effect depends on how many Assembly Drones you have. I would also recommend moving Mass Communion to tier 1 but have it require Unity Indoctrination it will make the Advent rebels have a distinct advantage on Culture in the opening portion of the game. 

Tier 2: I would leave Tier 2 alone as thats when we get our Temples of Communion and a lot of our Evangelism upgrades.

Tier 3: Put resource focusing here, even though I doubt it will fix the innate problems with it, a cost reduction could not hurt and may make resource focusing more easily accessible.

Tier 4: Move Expulsion from the security tree to the Understanding Tree. Its an economic advantage that doesn't really fit.

Tier 5: Move down Enhanced Focus, for the exact same reason as resource focusing to 3.

And thats all folks, there is pretty much nothing else for the advent to look forward too except Allure of the Unity which is in a perfect spot as is. It is the End game goal for the Eco players they will have reached there peak economy after finishing AotU. Im not sure if people would agree with these changes or not, but do give me your opinion as I would like to hear it. I might do a writeup on the Vasari as well but they are not as worse off as the Advent.