For me its certainly skill based combat, and by skill based I mean I want it to actually be significant. FX is also important, but if the game is fun and there is room for players to differ largely in skill, then I can turn a blind eye to "mediocre" FX.
Those are the big two things for me, but I really like the innovations this game is trying to make, so I'll most likely end up "trying it out" no matter what.