[someonesomewhere]

Simply Put:
Zone is different because it has new gameplay style and better graphics
If people were using graphics from UN:
1) From what I've heard, that's illegal. You can't take graphics from another server unless those graphics are included in the setup.exe download.
2) Having people using completely different graphics styles is stupid. That defeats the whole purpose of having different graphics styles on a server that you pay for than those that you don't.