I'm not sure I agree. Piercing Dissonance is three rounds of lag and is only slightly more damage than Vibrato. I believe it is also 10 less mana than vibrato. Basically, at hero, the mana difference isn't going to mean as much to me and I'll take the slightly less damaging vibrato with a chance to lag because I can sing it 3 times in 6 rounds to vibrato's 2 times.

The edge for Piercing dissonance is pretty lame too, in my opinion. At first, I thought that every time it shattered glass it would lag the opponent. That didn't turn out to be true. It lags you. Then I thought, well, if I can shatter a return potion or something it might be worth it, but, it isn't. It works so rarely you can't count on it, and then you're also looking at 3+ rounds of lag. Seems more like a flaw to me.

I never see anyone choose to use piercing dissonance over vibrato in pk at hero ranks. And I only used it in PvE if I'm trying to conserve mana.

Apocalyptic is a different story. To me, it really depends on the match up between you and the enemy. I'll sing it all day long against a giant or other low int race because chances are your going to get the doom version. Other times you are just rolling the dice and probably better off going with vibrato. Although, I will say when I played Jutley, 23 chr epic bard, I hit dooms often on just about anyone, including elves. It seems to me that there is a big threshold between 22 and 23 chr when it comes to people making the save with this song.