I've been vaping since October, and I think out of the 15 or so 510 attys I've purchased, about 3 of them worked really well.
Usually, they don't produce much flavor or taste burnt. Then they're producing tons of vapor but zero flavor from the juice. It's really a frustrating thing.
I've bought attys from NHaler, Puresmoker, altsmoke. I've used regular 510 batts and a protege. The juices are from Nhaler and DIYFlavorshack. The common denominator seems to be these attys...
When they work, they work wonderfully for about 5 days, then they only fizzle. No red coils, nothing (yes, I've drained them). I've never had an atty work for more than five days straight, even the good ones that worked. I've thrown away more attys than I've actually used. There is definitely some sort of issue from the manu. They were all legit Joye510 attys (or so I'm told).
I've used the same juice in 808 cartos, with better results.