* Yeah, I was kind of disappointed that some things were simply reused in GC2 from GC1. On first impression it looks like cutting corners, but I don't mind any more.
* The leaders animate in the full game, but I don't know what you mean by "silent", they never actually spoke in GC1.
* All techs have a flavor description in GC2, but you only see it when you finish research on the tech, so you'll miss it if you trade for the tech.

I guess GC2 doesn't completely obsolete GC1 (I kind of prefer how GC1 did alignment and morality), but I think GC2 is a much bigger and better game. The major additions are ship design, fleet combat, and playing as the aliens, and GC2 completely reworked (for the better) planetary development and the tech tree. And then Dark Avatar added asteroid mining, super abilities, treaties, and improved espionage. Plus the AI has steadily gotten better.

Also, the demo is based on the 1.0 version of GC2, right? A lot has been improved and refined since then, in the updates and in the expansion.

What I didn't like about Galciv1 was the immense weight it put on Planet Quality. If you got a low-PQ planet, you were SCREWED. And also how morale was uncontrollable.

What I did like about Galciv1 were Terror Stars and the ability to spam Trade starbases, even though I never actually did either of them. I also liked that Maso in Galciv1 was more challenging than Maso in DA.

Ok, thanks for the replies!

Is the leaders animated according to their mood like in Civ 4? For example, do they smile when they like you and look furious when they hate you now?

About sounds, I know they didn´t actually speak in Gal Civ 1, but they had some "alien sounds" characteristic for them. For example, the Torians sounded a bit like whales.

So does Gal Civ 2 have lots of new cutscenes not present in Gal Civ 1?

They are in the process of making a demo of the expansion. This should be a good example of the state of the current game.