You bring up many a good point. I admit now may not be the time for it. But I still dont think either of those have great virtual worlds. Maple story has an interesting look but the characters are a tad too diminutive, music is their strong suit as well as interface and battle class system.
Cyworld looks a little flat in comparison to Gaia though Quite literally. Something that did catch my eye was that they have an optional 3-d virtual world. Still, Zomg is largely composed of 3-d elements as well.
Perhaps in the future. I shall dream -,-.