I think it's a lot less "useless" now that every Hard dungeon has a random boss. It reduces the consequences of getting a boss like Tormented One that some classes have a lot of trouble with.
It also has interesting interactions with Vicious dungeons, like Demonic Library or Naga City that have a bunch of bosses. We could fill a thread with discussion on who to use it on in Naga City!
My only complaint about it is that it makes balancing Purist a bit more difficult.