i'm going to agree with light, up until end game it's pretty great then....it's just not. there's nothing to do except dungeons over and over and over or Wv3. fractals are ok in random groups until you get to the higher ones, then you HAVE to get a coordinated group or you'll wipe quite a lot.
edit: oh, and the final fight with zhaitan is really really disappointing. i hope they don't make the end fights like that in any expansions they might do.