First i want to say i fully support guiding new players to a dungeon, taking it slow, showing secrets if i know them , etc..
But when in rush farming mode, why do we need the story line. yes keep the doors locked and stuff so you need to do what you need, but stop the dialog waiting !
Frostvault for example, talk talk talk when we already have to deal with the dumb laser guy who wastes minutes of my life.
FH is an example of a good rush dungeon, no dialog in the way.
Dragonstar arena holy crap it moves sooooo slow. We could shave off 15 minutes if we just sped it all up.
Would be a great boon to players to give this as an option as a dungeon mode.