It is still well worth using in raid events, or any other pursuit with a finite duration (mission Time Trials, for instance), given that bards have ~no other use for that yellow bar. It takes 15-20 minutes to drive a bard out of endurance, during which time you basically have 2 more mana songs running without having to sing 'em, so that your group can burn a bit harder, perhaps even shortening the event into Dicho's meta-duration.
