Ironclad is easily the best gaming studio I've ever worked with. You want to talk about solid stuff. Even the beta testers can tell you that crashes in the beta were few and far between. Amazingly solid coding skills.
Stardock and Ironclad are a bit unusual in the sense that it's a far far more collaborative partnership than one typically sees.
For example, Ironclad is very involved in the Sins marketing both in terms of the box design, advertising, website (they pretty much did this website), and dozens of other things. Ironclad has a strong background in design and printing and this has allowed us to produce materials of a much higher standard than is typically seen in a much shorter amount of time than you'd normally see.
Similarly, Stardock has been very involved in the development of Sins both in terms of content and direction (like on the intro movie which was done by the same Stardock team that did the GalCiv intros) as well as game design where we took our strategy game design experiences and combined them into a master design.
I think one of the reasons why the game has turned out so well is that both teams have integrated our collective capabilities into a single bigger team. I think most big studios and big publishers would be shocked at the low-level integration of the teams. I'd go as far as to say that the integration of resources between Stardock and Ironclad is more thorough than some of the inhouse studios at major publishers between themselves. Seriously.