(Mar. 2011): I'm using the updated Steam rules. I picked it up primarily so that I could play with my wife, and I'm hoping we'll get the hang of it soon, unfortunately, you have to jump in with the advanced rules, which is a bit overwhelming at first.
The ships are a neat addition. I need another play or two to decide how much I like it. UPDATE (Mar. '14): It's a bit swingy, depending on if you draw one of the ships early enough, but bringing down a "ship hammer" on your opponent is pretty satisfying.
(Aug. 2011): I like! I have to say I'm getting a little worn out on Dominion at the moment, though. So I'm taking a bit of a break from it. I'm not entirely sure how this one stacks up to the other expansions.
Kind of a pain to get the wares cards and the other cards in the right ratio, but there's some neat variations that I'm looking forward to trying. UPDATE (Nov. '09): Now that expansion 2 is out, I don't need to worry about the ware/non-ware ratio anymore. Yay! (This rating only when using both expansions.)
It's hard to know how to rate this one. I'd rate the solo-play at around a 7--it's fun, but not how I'd prefer to play the game. The new cards and homeworld are great-they just add more to a game I already love, so that gets a 10. I haven't tried the goal cards yet, so that may change my final rating, but I think I'll give it a 9 for now.
(Apr. 2011): It's hard to to know when to pick a leader, but I tried it a couple of times in my last game and I won, so I guess they aren't so bad! UPDATE (Aug. 2011): I don't bring it out when teaching, but whenever all the players have played before, there's no reason not to include it. I tend to buy a couple of leaders per game, and it seems to work out for me.
This game seems to be infinitely expandable! This adds a little more chaos to a game that some might think is too predictable. UPDATE (Apr. 2011): I'm considering adding this in by default. I think it's probably simple enough to introduce to new players.