I donno. I have 2 ce2's that Ive been using, and I have had 0 problems with them. Mind you, I have only used them for a week, and refilled them about 5 times each. But no problems so far! I enjoy how they vape, and they seem to work great for me. I gotta say I dont like the price on them though. 5 bucks a pop seems a little on the high side compared to other things. Thus why I ordered up the Vivi Nova V2 today. Just like the stardusts, but with replaceable heads that cost 2.50 a piece. Seemed like a more affordable way to go in the long run. Plus I heard good things about it as well. Not so much on Vivi Nova v1's, but v2's are supposed to be pretty good.