Maybe I'm lucky, but after 2 months or more on BVC I haven't had a bad one yet. Each one has lasted at least two (some a little longer) weeks to boot!
I've seen so many bad heads around that I wonder how long is it going to be until I'm stuck with a bad batch. Because it already happened with Aspires and the BDC nautilus, is a mathematical certainty soon. I'm not rich so I try to buy as little as possible, so chances are slim.
I keep disposables on my arsenal because rebuildables fail more often than I care to think. Of course, my fault, but then I have the right to not rebuild if I don't want to. Bottom feeders are unreasonably overpriced and mechanical in nature, really, haven't evolved at all. And we continue to overpay with under performing vaping stuff. And very few people seem to care... I'm poor, I can no longer pay 30 bucks for an atty. Either start working WONDERFULLY well or I'm moving on. And no, clones are not a suitable alternative, as many times they don't work like the original or not work at all.