I vote for an Asymmetrical PvP (one player is always Empire/Dark Side, one or more players is always Rebels/Light Side).
I don't think the structure of a Co-Op game can ever be robust or responsive enough to bear the diversity of an LCG/CCG.
Basically, if we look at the "encounter deck" as a CCG/LCG player in the context of the aggro/combo/control framework, it can only effectively run aggro. It can't effectively run combo because it's "choices" are too random, and it can't run control at all, because it can't respond to player actions.
Therefore, strong combos are always going to trounce the encounter deck, and any "control" or "combo" effects the encounter deck randomly spits out are going to be countered by an intelligent player using control cards.
The only way to keep the game competitive between an intelligent player and a non-intelligent encounter deck is to hobble combos and limit player control effects (effectively reducing the game to aggro vs. aggro with some frosting on the side). But this will also prevent the growth of a meta, and ultimately limit the game itself.
My two cents.