Never thought I do it, but I made use of MRD skill in dungeon runs, I've so far done it in Halatali, Copperbell Mines and Toto-Rak (all low level), with Haukke Manor next. I joined up via 'Party In Progress' option in Duty Finder, as well as having european languages selected, I was literally in within a few seconds.
Not only that, I always aim to clear each dungeon in 30-40 minutes, as long as I keep up or the party keeps up.

If I continue to enjoy being on MRD, I may continue as MRD/WAR towards endgaming (after leveling the last remaining skill, ROG up to NIN job)