This is the best strategy game I've ever played. I'm eager for the next version V to be released this year....
Keep in mind this is a 4X game, lot of micro-management, you have to move every ships and fleets, decide what to build in each planet, which tech develop,etc. (there is a "governor" but is somewhat difficult to set).
For me it has two wakness : diplomacy/interaction with other races, is very limited (compared with Galactic Civilizations). The AI is a little dumb, even in the thoughtest level (it keeps sending ships and fleets to my well protected systems where I have ships with the ability to capture its ships)
Other plus : it is turn based, so you can play it at your own pace. The interface is quite simple, but could be difficult at the very beginning (so many icons!)
You can find mods that emule the entire Star Trek universe (want to fell the sensation of command a Borg armada against Federation?), Galactica (with emphasis in fighters instead in capital ships), etc.
As far as I have read, the new version is fully 3D, a la StarWars empire at war, and the AI will be much more challenging, whit lot of improvements....
Had you experienced the "Wait darling, just another turn!!" sindrome???