Player experience is greatly hindered by the fact. That the lag for players in different parts of the world is so widely different. A player in EU could think they're running, while, for the server, they're standing still while another player, closer phisically to the server, is beating the snot out of them. This is specially important given how PvP oriented this game is.
I understand this is not easy nor cheap to do, however I believe this'd help create a more diverse and definitely better player experience for those outside of North America.