I played a full game last night (Large Galaxy, Beginner, 5 AI), and I think the game is better than I originally gave it credit for. I'd say it's at least an 8/10 for me, and maybe it'll get better as I play on higher difficulties.
The biggest problem in the game, I think, is the difficulty of learning what all of the stuff in the game is and does. The game itself gives you almost no help or feedback in this regard. Some people have called for a "GalCivilopedia", but I'm not sure that's really what's needed. Rather, I'd like to see more feedback integrated in to the game itself, so that I can learn the game's mechanics while I play. This is one area where the Civ IV UI really raised the bar for 4x games, and I'd love to see similar things here. Here are some concrete suggestions on what would make it better in my view:
(1) All planetary production numbers should have tooltips that explain how they are calculated. The ones for Morale and influence are a good start, but I want to see where my production, research and taxes are coming from.
(2) The numbers that are there should show you the full story of how the value is calculated. Morale, for example, lists my bonuses and penalties, but they don't seem to add up to the displayed morale percentage. This may be a complicated calculation, but make it clear to the player how their buildings, bonuses, starbases, spending slider, etc. are combining to give them 47 research per turn.
(3) Any time a tech name is displayed (in the trade screen, in the full tech tree, in the tech select list), it should have a tooltip telling me what it does and what it costs. I should not have to left-click or right-click to check this out for a list of technologies. The costs are particularly important in the trading screen, so that I can figure out whether a proposed trade is a good one. Who can remember, after all, exactly how long ago they researched Xeno Ethics and whether it took a long time?
(4) Any time a ship or project is displayed (in a tech's description, in a buy list), it should have a tooltip telling me what it does. If it has multiple prerequisites, it should list them (e.g. what all must I research to build a battleship?). If it obsoletes something else (e.g. Research Academies replace Research Centers), it should say so.
Civ IV is really brilliant about combining (3) and (4) within the tech tree. Hey, I see I can research Civil Service, what does it do? <> Oh, it lets me use the Bureaucracy civic and build Macemen. What's a Maceman? <> Ah, a good unit, but I'll need to get Iron and research Machinery before I can build it. It makes the process of learning the game fun, easy and straightforward. I've played a lot of Civ IV, but I've seldom used the Civilopedia, because it's pretty much all there in the UI.
Anyhow, I hope that these types of improvement is in the cards for the patches. GalCiv is a big sprawling game, with a huge tech tree, a complicated economic model, and piles of planetary improvements. I think it'd be more fun and less work to learn all this if the game gave you some help along the way!
