Got to lvl 15 on my Nightblade, got frustrated with being too damn squishy in the dungeons for the amount of aggro I was generating via aoe spam (which I had to do in order to keep mobs off the healer). Long story short, switched over to all heavy armor and a shield for levels 15 to 17 and everything went much smoother in solo and group play. Should've gone Heavy from level 1 to get the all the passive bonuses. Will be doing that for live.