The main reason that I switched from dual coils to single coil cartos for my tanks was I often would get a burnt taste with the duals. After making the switch, I rarely experienced the issue again.
Part of this could be that I now know that I prefer a cooler vape. I find warmer vapor to be somewhat harsh. Therefore, I don't use low resistance coils, nor dual coils. Bottom coil clearos are more tolerable to me than top coils. This is just a preference of my own. However I can get a cooler vape, that's what I want.
Another theory that I have is that the top coil in a dual coil cartomizer may not get enough
juice after some
vaping with it. The top coil would be located at about the middle third of the carto tube. As you vape, suction pulls
juice downward from the polyfill. This is why the filler appears dry looking after a few vapes; this is normal and unavoidable.
Normal wicking from the tank does not replace all the juice that is vaped from the carto, but it does keep the bottom coil area wet because that is where the holes in the carto are. It's possible that the juice doesn't wick all the way up to keep the top coil wet, so it ends up eventualy burning the filler and causing a burnt taste.
Anyway, that's my thoughts, and I'm sticking to it. Vochslu, switch to single coil cartomizers and see what I mean.
