I decided to go ahead and purchase GalCiv. I figured if it was bad, I wouldn't be out too much. Anyways, it took me a couple of games to get the hang of it - the different sliders, constructing/purchasing, the importance of early colony ships, trading with other civilizations, etc. After figuring things out I was able to play a couple small maps successfully.
I have enjoyed the game, although I still don't fully understand everything and am definitely still learning the game, but it was certainly worth the $4 I spent and probably more. It has certainly raised my interest in GalCiv2, if the sequel plays similar and is improved (building your own ships sounds cool).
I guess I have one question, and it probably applies to both - Does anyone that has the expansions, play the original games, or do you just play the expansions?