Age of Expansion tech log and honest opinion.
;-)
GalCiv3 Forums
I've played for a while and before I get to much to far ahead I'll fill ya all in, and whatever else I've gathered in 108 turns about ¾ through the first age:
Turn 1: Xeno commerce.
Turn 2: artifact +25% Xeno commerce.
Turn 5: artifact completes Xeno commerce.
Turn 5: planetary improvement.
Turn 9: another artifact +25% planetary improvement.
Turn 11: planetary improvement completed.
Turn 11: Accelerated growth.
Turn 22: Accelerated growth completed.
Turn 22: Xeno industrialization.
Turn 29. Xeno industrialization completed.
Turn 29. Wealthy population.
Turn 37: Artifact +25% Wealthy population.
Turn 46: wealthy population completed after...some problems which I will elaborant on later.
Turn 46: weapons systems. (made destroying all 5 iridium shipyards from all five planets easy 
)
Turn 51: weapons systems completed.
Turn 51: Xeno economics.
Turn 51: artifact +25% Xeno economics.
Turn 61: Xeno economics completed.
Turn 61: militarization.
Turn 66: militarization completed.
Turn 66: research specialization.
Turn 74: research specialization completed.
Turn 74: interstellar travel.
Turn 81: interstellar travel completed.
Turn 81: agricultural adaptation.
Turn 92: agricultural adaptation completed.
Turn 92: interstellar banking.
Turn 105: interstellar banking completed. (unable to research economic focus due to age barrier.)
Turn 105: defense systems.
Turn 108: defense systems completed.
-I have hit a ceiling at interstellar banking. I will likely hit more at other various points of the governance branch, if all techs were working maybe other branches too. And likely the age of war will be even more squeezed for me. Not to say this will always happen, as it's intriguing to think if I didn't hit the tech barrier, would it have a purpose for the player? Even if it helps the AI it could easily be invisible to the player and allow free research once again.
-I hit some problems between turns 29 and & 46. Research was going slow due to outdated improvements so I upgraded...
When upgrading a few low level improvements on a low production world the current system works good. (it being to build factory Lv2 you have to build factory Lv1 first.)
In the mid late game as production rises and improvements bonuses get high things start to suck and slow down real fast. Simple example:
A class ten world with 5 new xeno factories being built. Enough production exist to make a Xeno factory in one turn, the problem is you have to make a basic factory first thus doubling your build cue to 10 turns to complete. The more production the more this will hurt you and actually slow you down. A planet doing the same thing with low production will benefit when a low level factory has to be built first because there is still production being modified by the factory while its upgrading thus saving turns. A factory is still a factory. 
I for one think this could be easier by buying the first factory on a new world like in galciv2, or when smart people would build Xeno and advanced factories instead of building the mega factories to start out. I think the system should be changed.
-Tech creep sucks, I researched "research specialization" (+10% global research) at turn 66 and it made interstellar banking 22 turns to complete instead of the previous 20! Which is why I put it off for so long because throughout the game it seemed planted at twenty turns no matter if my research increased. :/
-Oh and production lines are still visible through the fow making finding enemy shipyards easy, which is how I kept finding the iridium's shipyards. :3
Well I think that's it for now, its not as scientific as other posts but I hope its clear.
DARCA.
) and then whatever Lv of improvements AFTER the basic factory because its faster to build and the bonus is pretty damn good get started. After that happens points 1-3 occur, making the current system a bit broken though.