Open world, when done well is incredible.

http://www.youtube.com/watch?v=HeR7D1PfbQg

When it is done poorly, like hunts, it is terrible. Btw I hope the devs can take a look at how open world bosses were done in GW2, no rendering issues even with hundreds of players, there is a sense of danger with their abilities, they don't drop like a sack of potatoes even though they are elites, and they offer equal rewards for participation.