It really wasn't so much the VVN itself, but my preferred juice. I vape sweet, rich, buttery flavors, like butterscotch, caramel, etc. It appears that the VVN doesn't vape that stuff very well.
When I first got it, I was happy as a lark. It seemed to work perfectly. Then it just... stopped. I understand variable voltage, so I was using the proper settings for each atty. But all three popped on me within 48 hours. I know I could've gotten a bad batch, but that's highly unlikely. Again, I blame my juice flavors.
I managed to resurrect the 2.8 ohm atty, and used it exclusively with biscotti from Vaporcast. Good taste with that, but weird reactions. The VVN actually zapped my bottom lip and my tongue. Yes, an electrical shock. Also, I noticed it flooded very, very bad from the bottom threads. I never overfilled it, and I made sure the threads were flush when I screwed it in. It still leaked.
But man oh man I love my carto tanks.