I have Sins. Its okay. Like Vidmaster said, tactics are meaningless in Sins due to its scale. Of course, it does have several mods in the works for it. There is a Star Trek TC which has some of the team from the HW TC, a Star Wars TC (made by EvilleJedi, guy behind Warlords for HW2), there is The Last Stand by a guy known as ManSh00ter which aims to be an unofficial expansion for Sins, and there is 7 Deadly Sins, which can only be described as Sins's Inferno. I really can't describe 7 Deadly Sins properly as its size defies description.
And if 4X games are being mentioned in all of this, Sword of the Stars and its two expansions need to be included. It has excellent gameplay, incredibly diverse factions (they even have different methods of FTL travel), and it has some of the best real-time space combat with Newtonian physics and real-time projectile tracking. And the dev team for Sword of the Stars worked on HW, HW:C. and the original Ground Control.