One thing that made the lower level toons life worse was the difficulty scaling up for lower lvl raids: reavers and shroud. As those are ran all the time by capped toons, the scaling up in difficulty on elite reavers and overall shroud to make some match for those capped toons made the job for the first lifers ~17 lvl really difficult. I don't see it as such a bad thing, but really wiping an entire lvl 20 party on a 17 lvl raid on normal is weird. Also a mass spawn of air elementals knocking and slowing lvl 20 people without saves on reavers is annoying.
Now about LoB, considering AC wise (I know its another thread, but...) the raid is too hard for the normal difficulty.
Every other quests are fine, I think.
But what I really would like to see is differing difficulties on epics, may be for levels as challenges, or something more like the casual, normal, hard and elite.
I think that Shade's post here has some nice suugestions for this matter: http://forums.ddo.com/showthread.php?t=307339