I have only played the conquest campaigns in Orion Pirates not EAW. I have been asking around on two different forums and everyone says that the conquest version of the game is essentially repetitive. All you do is fly around completing missions. There are no signs that you are having any impact in the game except for the change of hex color. I eliminated the Federation, Gorn, Hydran, and Mirak and I did not receive any indication that I had done anything other than change the color of the hexes. The only empires left were my allies, the Klingons, Lyrans, and ISC. I played as the Romulans. I played 700 missions and the only credit I got was the green colored hexes.
Is it supposed to be different in EAW? I recently installed and patched to the latest version, but I have only played skirmishes.