Racial choices aren’t just for decoration anymore.
The expansions, Dark Avatar and Twilight Of The Arnor, have tried hard to address that issue. The lack of variety among the races was one of the major complaints about the game, as 4X space strategy games have traditionally offered an array of diverse and interesting racial choices.
The tech trees were exactly the same, and everyone had the exact same structures and play-styles. Some races were given better bonuses than others, but even those differences were minor. When Galactic Civilizations 2 first hit store shelves the race you picked was nearly inconsequential.