Personally, I try to nurture a mistrust of myself to not make involvement in a persistent MMO universe of 4X and deception too high a priority in life. But I have pre-ordered GC3 because it has massive potential and gives me time to graduate first. And then I intend to never start a new game again. The last thing I played was X3: Reunion, and was looking forward to a rumoured MMO version of that, because I assumed EVE is starting to look a little bit dated, or is it? I won't be disappointed if GC3 turns out to not be MMO because I predict the fan-fiction aspect will run and run. We could, for example, narrate it with elements of Warhammer 40,000 Universe...? http://warhammer40k.wikia.com/wiki/Timeline_of_the_Warhammer_40,000_Universe
So this is the place to speculate and share rumours of 'the-next-big-thing' for MMO strategy gaming in a 3D universe.
My suggestion is that it's not possible for any one standalone game to satisfy your craving for truly open-ended 4X