The best way to compare this weapon with the other weapons of similar itemlevel will be to sim it in EnhSim, as soon as the updates are finished (Raged deathbringer proc will hopefully be added to the EnhSim in next version)... Untill then we can get a rough idea of the dps the proc brings, following maths like the above poster, but thats about it.
I'm curious as to see if its a worthwhile weapon for us, given that it is the only 2.7 weapon of that ilvl. The only thing that would bother me... another source of burst! Gief some streamlined dps! 8)