Those economic sliders really make the game too easy ; the AI cant deal with them very well, it seems. When you know what type of ships your enemies have (through espionage or other means), you just have to put your research sliders on 100% for a few turns, research all the weapon or defense techs you need (knowing what type of ships your enemies have) ; then you put the military slider on 100% and pump out your new ships like mad. It's really fast, and the AI wont adapt to it : you can (and will) dominate the galaxy very easily. By juggling between 100% research and 100% military you can make every game a cakewalk.
I dont know what could be done to balance things, maybe changing the way those sliders work? Or maybe making the AI use the same tactic?