Just wanted to say, I bought the download version of Sword of the Stars early yesterday and have been quite enjoying it. I ended up playing it for about 8 hours straight.
Took a little getting into at first as the demo tutorial is kind of weak, but I'm glad I persevered.
The technology tree is mostly the same for each of the 4 races and is slightly randomized for each player in each game (some side techs will be available, others won't), but each race has enough other differences (the main thing being methods of travel) to make things interesting as each race.
As a side note, I got it from GamersGate, whose downloader program seems a bit crude and underdeveloped. Still, considering the other download version is from Direct2Drive which apparently has to connect to the internet to check your registration every single time you play the game
(from what I could gather from reading their FAQs), I'd still have gone with GamersGate.
Also GamersGate was the latest purchasing option made available for M&B, so it seemed more fitting to go with them.