After clearing tier14 don't you think that the three final bosses are too long (nowadays Will of the Emperor is not a long encounter but it was when only MV had been released)?
Heroic Will of the Emperor > 12 min
Heroic Grand Empress Sheek'zer > 14 min
Heroic Sha of Fear > 17 min
I strongly prefer 10 min fights, no problem if they are extremely hard ones, but no longer than 10 min. I would like to know your opinion about this