Sword of the Stars is more of a space combat game than a 4x IMO. There is little control over planetary makeup, the tech tree is focused on military advances, and diplomacy against the AI is limited.
Having said that, I find this game to be a blast. I really enjoy both the tactical and strategic aspects of combat. It can be a little repetitive, and you don't have as much control over the behavior of your units as you might in other games, but for me it was a blast. Just know that it is brutal and you will lose a lot of ships. This game is a battle of attrition and who can get there "first with the most".