Sins was fun when I played it, but what has been alot more fun and alot more interesting, imho, is Sword of the Stars, and their expansions. SOTS 2 is in the works and promise to be epic-grade stuff, I can hardly wait.
While SOTS I is a pretty damn good game, my two biggest arguments about it is borked AI and all 'solar-systems' comprising single planets... fucking boring. Setting that apart however, it's a pretty damn good game and in multiplayer the AI issue can be removed entierly if only players take part.
Other than that, expect the AI to ignore Destroyers and for the most part, cruisers, in favor of Dreadnougt spamming when the tech is available to them. Also expect them to totally ignore any and all defencive fleets around planets in favor or sactifising perhaps dozens of ships to burn it down, THEN perhaps shooting the defenders. Absurd shit is absurd. SOTS 2 allready confirmed to fix the planets issue and likely fixed the AI issue as well, beyond generally improving everything else and making it a greater 4X game.
Have fun in Sins, folks. I've not touched that game since last year iirc, and I don't currently have it, either.