[AstralWanderer]

SEV offers a vastly superior tech tree to GC2 and far more detail generally (the exception being planetary developement - with SE you purchase facilities until the planetary limit is reached). In particular, areas like ship design, race/empire setup, intelligence and combat (space and ground) provide far more options and issues to ponder over.

On the other hand, not everything works as it should (though with the patches, things are much better, hence the poor initial reviews), the UI is clunky and the AI fairly anaemic (even with mods).

Based on previous form, SEV is likely to get more updates (SEIV was receiving updates 5 years after its initial release) and there is no "online activation" hassle (something which I greatly resented having with GC2's patches). As such I would say it is worth a try, though I think the demo is still based on an old (buggy) version.

SEIV does have a polished UI and mods aplenty, but suffers in areas like tactical combat and ship design (though still better than GC2).