For those who really like tactical battles there is Sins of a solar empire and Sword of the Stars.
What I did not like "much" about Endless space Card system is the large part of it that is based on luck or randomness initially, Until one of your opponent becomes predictable to the point where you can use the same strategy against them over and over and it works every time.
Ex: You use a fleet with mostly long range lasers. Opponent uses a card to boost Shields to counter your lasers. You know he will use this card so you take a card that counters it. It is super effective.
Repeat every next battles with this opponent.
The system might be more interesting in PvP but against the AI i think It got pretty bland rather quickly.
I am eager to see what StarDock are cooking for us regarding the battle system in GalCiv III