I am testing out Smoktech's triple coil cartomizer. It actually gives a pretty good vape at around 5v, but I also emptied out a 3.5ml tank in a little over an hour. Only way to consume juice faster is to suck it through a straw. It gives a lot of vapor and fairly good TH. But in all honesty I think about the same about the single coils and they don't go through juice nearly as fast, or battery power. The subjective amount of vapor production does not seem to be proportional to the amount of juice consumed. Not sure exactly where all that extra juice is going.