It's been dominating my gaming for about 2 weeks now.
The biggest obsticle you'll face is the learning curve. The manual is inadiquate, and the in-game tutorial is terrible (just a sequence of movies).
There's no multiplayer, if that matters to you. (I read a justification for why not on their boards. Mostly it's because, typically, multiplayer consumes a tremendous wedge of the budget, and is only used by about 5% of the buyers).
I highly recommend the game.
Features include:
An extensive tech tree with niche technologies that can be researched independently of all others. For example, you could focus entirely on diplomacy and never touch a weapon tech, or focus on warfare and totally ignore trade and diplomacy. You can specialize in engine techs, or sensors, or just generalize and have a well-rounded civ that doesn't excel anywhere. I like this because it really lets you focus on your strengths, if you want. A civ with research and economics bonuses can really capitalize on the research and economics tech trees, and become a real powerhouse in those areas.
The second feature I'm just in love with is ship design. From a few basic hulls, you can design whatever ships you want. You can stick extra engines on them for speed, or focus on life support modules for range. You can make a slow, clunky ship loaded with weapons, or super-fast colony ships. There aren't many pre-made ship designs because there's no way to know what techs you'll have. So you really have to mold your fleet personally around what techs you've discovered. Also, there is a whole mess of purely decorative pieces you can slap on the ship to customize its appearance. Some people on the GalCiv forums have gone way overboard, sculpting huge battlemech-shaped ships or equally complex designs, just for the hell of it.
I could go on, and probably will if you ask any questions. :p Just about the only thing I wish was there that isn't there is a 3d-galaxy map, with a Z-axis. But I don't think they want to confuse people too much - most people think in 2-d much easier than 3-d.