So i use this as my main nuke on my wiz, normally not without GoRM active because of the cost. But with the anniversary/revamp zone armor you get 40% boost to spell dmg, add in the wizard dmg pet (mine does 30%) gives a nice 70% dmg boost to these spells. They DO stack to a wonderful effect.
I get crits for 22-29k in group combat. So far in raids i have gotten a 33.6k for it.
If you get the SolTeris raid robe gives this spell a 70% bonus, with my 30% pet, thats 100% increase! with bard/druid helping, thats a lot of dmg. throw in the fury of ro AA can get a REALLY nice hit from this spell.
Will try to post back when i get the robe for more info. This is all at level 75 btw.... 22k for level 75 is unexpected in group combat.