Just bought this game last week, based off the GameSpot review, which was a surprisingly strong recommendation. My impression before reading the review was that Galactic Civilizations was an outgrowth of the older shareware space strategy games, and as the gap between shareware and retail has been widening considerably in recent years, I was cautios. The game has turned out to have production values certainly in line with current retail releases, but I've been surprised at how enjoyable the gameplay is.
I think one area where the game has succeeded has been in cutting down the scope to a reasonable size. The physical size is certainly accessible--galaxies are a few dozen systems, not the hundreds and hundreds of systems found in other space conquest games. The smaller galaxies encourage more complex strategies, other than the typical "whoever expands quickest wins" as found in some of the other, older titles. The tech tree is also accessible, with enough technologies, but significant advances associated with most techs and very few "filler" technologies. Research also takes reasonable time, which gets away from the "technology outdated before you've had a chance to even use it" syndrome.
The one thing that put me off is the tile-based system. I realize tile-based systems are still used by respected strategy titles, most notably Civilization IV, but it seems that a vector map would be more appropriate for a space game. There may be AI reasons to favor a tile-based map, but a vector system just "feels" right for a space game. In any case, it's not a serious distraction, and the game plays well even with little oddities like the planet from one system being closer to the star from another than it is to its own sun.
Of course, I think the ship designer is fantastic, best in a strategy game to this point. The smaller fleet sizes takes some getting used to (I'm accustomed to fleets of 50+ ships from other games), but it's consistent with the game's attempt to focus the scope so the game becomes more about strategy and less about managing spreadsheets (although spreadsheets can be fun . . . but I digress).
The one feature I'd like to see would be the ability to copy an existing ship design into the editor, which would make updating designs much easier. It would also allow me to see how the default designs were put together . . .