If you like GalCiv2, odds are you'll like GalCiv3. I was in since the original Alpha, I never found it to be as buggy as people make it out to be, even in beta. By the release date, I wouldn't hesitate to call it very solid from a stability point. I don't recall getting a single crash or hang with the release version nor do I recall much in the way of glaring bugs. Most of the complaints I saw were from people who didn't meet the minimum system requirements or were sitting at the minimums. They aren't joking with the requirements, check them out before buying.
I wouldn't necessarily say Stardock doesn't deliver on what THEY have in plan. I would say Stardock often doesn't deliver on what their customers have in mind. Brad (aka Frogboy on the forums) is VERY enthusiastic when they announce a new product. That spills over into their fan base. That enthusiasm causes the fan base to have to have very high expectations. There were many threads on the forums back in alpha of people whining that "I expected it to have feature X" purely because they wanted it, not because Stardock made any mention of it. With a few exceptions (I'm looking at you Fallen Enchantress), Stardock is VERY consistent with what you get with their games.
+ Continued patch support after release
+ Developers that actually listen to their fans
+ Some level of mod support
+ Solid gameplay
- Artwork/graphics is very MEH, mostly the UI.
- Not much new from a gameplay perspective.
Plus the typical Stardock humor/jokes which you either love or hate.