All my other abilities seem kinda meaningless next to it?
only the case early during leveling.
I’m in torment 3. It out does my other abilities by A LOT.
what build are you playing? as far as i know there are actually some builds that can make heavy use of it 
Spiritborn poison build.
ah! yea i think i saw something there ^^
the boss powers can grow pretty strong. dont forget they also scale with your paragon level.