I got a pair of these today. I filled the first one and started to vape, but apparently I got a reject, becasue it won't draw at all. AT ALL. it's like vaping a pencil. I'm not talking stiff draw, I mean zero. I'm gonna pull it aprt tomorrow and see if something is put together wrong. Undaunted, I withdrew my Crushed Caramel Apple juice with my trusty syringe, and filled the second one. No leaking thus far, mad vapor (when it hits right), excellent flavor, and surprisingly warm vapor. I can't be too bent out of shape for the dud, it happens sometimes, no big deal. Overall, I have to say these things work very well. The only issue I have is that I can only use it on an ego battery. For some reason, the 510 to ego adapter that I use for stardusts doesn't fit these guys, so I can't crank em up. (WTH) But that's ok, they perform well at 3.7.