I've played a few games of DA so far and I have to say that it makes GalCivII feel new again. Here's my thoughts on different aspects of the game:
The Stardock Logo At Startup: I would just like to say thanks for not giving us a million video clips to skip through with each game start-up. I'm also playing Neverwinter Nights 2, and there are no less than 5 logos that I have to click through to get to the main menu.
Asteroid Fields: These are fun. I like how they impact planetary production and that they can be culturally flipped--a loss of a planet to high influence can be quite drastic, its cool the asteroids can change hands before things reach that point. With asteroids and constructors, there a lot of space build up that can be done which keeps things interesting in times of peace.
The Constructor Starbase Radius: I like this a lot! It takes a lot of guesswork out of my starbase borders.
Explosions: These rock!!
New Ship Pieces: See above!
Music: I like the new main theme. Is some more music going to be in the final version? Also, even with my custom soundtrack I find that the background music can get repetitive quickly. I've mention this before, but there should be a key to randomly select a new music track (and so my ears don't have to wait the annual UP meeting).
Neutral Alignment: IMO, this alignment was much better than good or evil--reducing their auto-terraforming ability makes it much more balanced.
UI: I'd like for the planet type (radioactive, etc) to be displayed somewhere in the colonies tab of the civilization manager. This would make it easier to see what tier 2 colony tech I should research to optimize my planets. I'd also like a race's super ability to be listed somewhere in the stats & graphs section (for your race) or the foreign stats section (for other races). But overall, the UI is solid and I could find my way around the new features a few minutes into my first game.
Base Race Abilities: I've only played one game with this feature added, but it can make some potentially big changes to gameplay. In my game, I played as the Iconians and got a base tech bonus of +20. But then I could (and did

) buy another +20 research bonuses with 4 of my 5 discretionary point , and finally I got another +20 from my political party. I'm not sure if this functionality is intended--or exploitable--but it was interesting being a research juggernaut.
Super Abilities: The Iconian's super ability seems quite underpowered. Unless I'm missing something, super-adaptable simply gives 2 colony techs. It should at least give the advanced versions of these techs too, if not something else with a little more pizzaz.
A lot of bruhaha has been raised over the Drengin's super ability. While I have not yet played a game with them, here's a possible fix: rather than give them freebie ships every time war is declared (which can be exploited), let them recycle a percentage of their destroyed military ships. This would give them a lot of military endurance, so they could gradually grind down their opponents. It also would eliminate any problems with inappopriate or outdated ship designs.
Anomalies: These should spawn in periodically throughout the game, to give our survey ships something to do mid-game.
Eyes of the Universe: This is just way too useful and makes sensors obsolete. Another way to implement it would be to give your planets (not star ships) a large sight radius. Still useful, but no replacement for sensors.
Overall, the beta has been reasonably stable and a blast to play. Nice work, Stardock!