I got a level 30 version of this legendary grenade mod the first time I beat the final boss, but the base damage seemed incredibly pitiful. I still decided to equip it for kicks to get the All Decked Out achievement, especially since I have almost never used grenades up until this point.
I'm only about 15% of the way through TVHM and I got ambushed by 3 level 37 Rabid Skags which KOed me in record time despite my being level 41. In desparation, I threw the grenade at them and next thing I knew, I got Second Winded, all 3 of them were wiped out *and* I almost fully regained my health.
I can only imagine what higher level versions of this grenade are capable of, I was originally kinda miffed when I failed to obtain a CC from the final boss and only this particular legendary, but it's still pretty good.