One of the few moment i use this ability full time it's A5S repeated 5 shock therapy where everyone is stack and 10% mitigation is quite nice
It allow your partner to catch his breath and start working

But it can only work for 2 shock out of the five but wheel can last during almost all

As Powe said adding all diurnal HoT, a bole if you have and time dilatation in your tank/MT is quite a relief
(Especially on Hummel Faust XD)