Have been using one from COV for 5 days now and really like it. No leaks at all no matter how it's oriented...so far.
Blew out the primer and had great taste and vape from the very first hit, I was impressed.
It does seem to blow through liquid much faster than any of my other solutions but I like it.
After my 2nd refill, probably halfway through, it got extremely hot and no vape, I kept doing primer puffs but no luck, removed the tank and reinserted a few times, no luck, refilled no luck, laid it down for about 5 minutes and it was back to normal for another refill or two.
2nd day vaped just great for a tank then dry again, I'd say I went through about 5 tanks at this point, yes I chain vape. So I gave it an alcohol bath but it was clean. Blew it out, dried it, dry burn x2 (3 seconds each) and saw the red glow on the side reflections so plugged in a tank and it went great for about 3 more tanks then dry again.
Refilled it and laid it down on it's side for the night.
Next morning it vaped like a train through half the tank then dry, refilled and laid down for maybe half hour and it was good again.
Now I seem to be getting a little better at the priming and taking slower hits. Also using a little thinner juice now at about 70/30. I usually run 50/50.
Overall, very pleased. I usually have about 5 different pvs all going at the same time...Infinity, eGo, Riva, box mod, 510 all with different ends...drip, carto's, ce2's, etc. I like variety and stability. If one doesn't work when I grab it, the next one in line better or it gets launched haha. But I have noticed that I'm reaching for the tank the most often now so I guess that means I like it.