Just recently finished a long 66+ hours insane map that I been playing off/on for over 3 months.  This game was prior to 1.6 patch so there might have been some changes since then.  I'm very disappointed in the AI of enemies.  The begging game they were very active and engaging. Mid game they kinda slacked off a little and would only have minor skirmishes with each other.  By end game they were basically just waiting for me to wipe them.  They would only build constructors and send them out to resourse areas.  I'm comparing my experioace to GC2.  I used to love having long prolong games and just watch what the computer would do.  I would be basically the only super power and watch the other empires fight it out in there little skirmishes.  I would intervine if one got a little too powerfull.  Yes in GC3 that didn't happen.  I was basically the only super power and they would just build constructors even tho they were at war with each other.  I think they just went belly up as soon as I was powerfull enough.  I wanted to see them grow and adapt like they did in GC2 but I think the AI is just not there.  I did find out that there is a hard cap on income basically you can't have over 999,999 income .  I was impressed with one of the last planets the YOR had that took 3 waves of 12 transport ships and finnaly fell.  Also the ending cinematics were weak and basically spent most of the time on the credits.  I would have much rather seen a better ending..  I'm going to hold off on the Mercenaries expansion for a bit till all the bugs are worked out but I did buy the precursor worlds and mega events packs and started a new game.  Hopefully these addons along with any upgrades in 1.6 patch will make this next game a little better.  One can only hope...