It playes a great deal like a slow paced Supreme Commander in space, with a bit of Homeworld and some very light 4X elements thrown in. It's got a steep learning curve, especially if your background is solely in RTS games.
I humbly suggest that a large part of that success is Stardock's (well deserved) excellent reputation, rather than anything specific about the game itself. Another large part is that it's a slow season for PC games, no offense, and that the advertising and available info about Sins (deliberately or not) paints it as all things to all strategy gamers. I bought it, suffice it to say, expecting something more strategic and less like a traditional RTS.
