My experience with Stardock download, for the past 18 months (at least), has been extremely positive : always a 750 to 825 kb/sec speed (on my cable connection), and no disconnects (or errors) whatsoever.
That is one of the many reasons I have been very happy with Stardock service -- since the GalCiv 1 beta. It is really not fun to wait hours, or to see a 90%-complete download crash : that has never happened to me with SDC.
(I'm not paid to say that, I am not friends with anybody at Stardock, and it is not my intention to become a FOB -- friend of Brad, not friend of Bill Clinton.)