Doing some theoretical math just to explain easier. In pvp videos people have around 10-15k hps, so let's assume our sorc has 10k hit points. Parasitism, tier 2 talent, with 2 points gives us 1% health back when dots crit. So the 10000 hps sorc will get 100 health per crit. Now we zoom up to tier 6, almost as high as you can go, spend another 2 talent points to get 20% more healing. So the 10000 hps sorc will get 120 health per crit(yes I know devour works on death field).

Is this how it works in game? Never took parasitism during the beta. Do we spend 2 talent points at tier 6 to get 20 out of 10000 hps back on a dot crit?