Will simply depend on whether bosses or trash are easier to kill. In dungeons, the choice will almost always go to casters, as an Caster LB will deal 75% of a Melee LB to every enemy, without fall-off, while a player AoE tends to average 40% at most of their average single-target potency output. And yet many casters still fall under the misassumption that LB is a "boss thing".