On raids, if enough bards about, then it's been fun to alternate the odd large nuke in. Only if resists are being brought down as a resist will hurt. But if you've got time to rotate round a few songs, are clicking other things to break the melody, and everything else covered, then it can be a bit extra when burn is called on a mob. If you've got enough for a fade, then the rest of your mana pool is something that could of added a bit more dps.