I was recently playing SEIV Gold, and I had only 3 systems... However, without cheating I had a sphereworld, 2 ringworlds, over 2000 large fighters, over 300 baseships, 100s of large weapon platforms, 1000s of large troops, and only 2 more technologies that weren't completely researched... I believe I spent around 25 hours to accomplish this, tech research was on slow, the galaxy massive, medium number of races, difficulty was hard with a high AI bonus... Turns were taking almost a minute just for the AI to move, and I'm on a pretty fast machine.
I was about to unleash my massive force and crush the entire galaxy!!
And then my stupid filesystem got corrupted and I had to resintall windows =/
