I use 3ohm boges between 4.7-5.0 volts on my provari. When i ordered the liquinators, i got a few preslotted cartos as well. Those worked much better, i got several days out of them, and as you said the taste got muted over time but they never tasted burnt. I don't have a dremel nor a saw capable of cutting steel, so i've got to punch my cartos. Not sure what i'm doing wrong tho. I've watched a few videos about punching cartos and theyre techniques are pretty much similar to mine.