Did you do the elite quests? Most of the elite quests are a joke (most of them are 2/3 players), plus the elite quests give really nice xp and gear. The circle of blood in nag gives some really good xp in it, but i was unable to do with my 5 toons (gear wasn't that good). I killed the first 1 no problem and barely killed the second one. The last couple i had help.