Running up to kill a quest npc and finding it dead, killed by a character from a different realm, and having to wait for a respawn is one of the worst things in this game. Also leveling gathering professions or just farming mats - the world is stripped bare.
Squats and bulking made my pants too tight. Thanks a lot, now girls can see my small package pressing against the fabric. - ChopSocky
Lol, I was just in outlands today with my alt trying to keep my mining up with my level. So from 58-70, trying to keep up with the farmers on their 280% mounts is near impossible.
Speaking of nodes and the cross realm zones, I also have a complaint about when you're on a flight path. On your way to the destination, you see a bunch of nodes you can hit up once you land, except once you land it puts you on a different realm than the nodes you saw. So flying back to those spots is pointless. This has also happened showing me a rare spawn while I was on the flight path. Soon as I land, I fly to the spot and no rare. Wasn't dead, nobody took it, it was just gone. Later, took the same flight and the rare was still there until I land. Quite the bummer.