From a PVE standpoint, ER > LoH.
lets assume you have the minor LoH glyph, reducing cd to 15 min. 100% hp every 15 min right?
ER, 3 min cd. 30% hp.
ER restores 150% of the warriors HP every 15 min potentially whereas LoH is 100%. If your not glyphed for LoH (it's a minor glyph so i dont see why you wouldnt...) its 180% of the warriors hp over the timeframe
LoH - omfg i killed this ret 2 1/2 times before he was able to kill me their OP!!!! nerf bubble or loh nao!
ER - This warrior popped shield wall, shield block and/or spell reflect, then ER... meh it's just 30% hp we'll get him.