Well, I didn't like doing all the micromanagement that you had to do.
There is still a lot of micro management, however, it's getting better, especially with patch 1.7 and the new constructor/star base improvements.
ou couldn't leave ships idle
Just place the ship in guard mode and move on. It will stay that way until you move it, (although sometimes in the current build if you add a ship to it's fleet you have to put it back into guard mode but, Stardock has said this is a bug and would look into).
your planets had to be producing something or have 0 social production
This is true, however, just put it in special project mode and let it go, forget about it unless you need it to do something.
where you placed your planet improvements mattered because of adjacency bonuses
Adjacency bonus's can be a pain and, even though it does add something to the game it almost forces the player to specialize planets. Although I find that most planets have two clumps of tiles next to each other which then allows you to prioritize in two areas. I personally am not a big fan of overall adjacency bonus's, especially in general research, production, economy, ect..., however, I like the bonus production that hives give adjacent things ect...
terraforming was a pain because you could screw it up badly, etc.
Terra-forming has improved, mainly because they've reduced the unlock any tile terra-forming options. This now allows a player to unlock tiles as they become available versus just having one of these unlock all terra-formers and want to wait to see what the other smaller terra-forming tiles unlock first. I don't see this as a problem anymore, however, you must keep in mind to unlock tiles near other tiles or place it in a place that will allow a single tile to be connected to the larger group so one can get adjacency bonus's.
I could finish even large GalCiv 2 maps in a few hours
You're awesome, always played epic games in the largest Galactic Civilizations II maps and even more epic games in Galactic Civilizations III, never finished the largest map games in a few hours.
That is more or less what I liked to in GalCiv 2, play through a map as though it were a quick game of chess.
The smaller maps still allow this, I've played smaller Galactic Civilizations III maps in an evening. Although I've only did that once or twice mainly to test certain things and even that I don't know if I actually completed it, I may have stopped short because of old bugs that have since been fixed.
Overall, give it a good try. Look at the benefits of the adjacency bonus, instead of the down side. This game does still have a lot of the feeling of Galactic Civilizations II and I feel it will get even better and, will eventually surpass Galactic Civilizations II as great games. It has a ways to go, including squishing a lot of bugs that is still on a long list somewhere and will eventually be gotten to but, for now enjoy.