I bought a pack and they are pretty good. OK, very good. I do mine differently than everybody else. I take a new one and pull the 510 connector with guts from the tube. Then the other stuff comes out easy. This step takes less than 30 seconds.
Dry burn at low voltage for a few seconds to burn off anything on there.
Next I take all the parts and clean in everclear in a small container with an ultrasonic cleaner from harbor freight.
Take out, blow both ways on the center tube, and pat dry on a napkin.
Untwist the wick to loosen it up, it will go back to shape, but this loosens it up a little.
Then I assemble as it came from the factory except, I don't push the clear silicone plug all the way on, I leave it about 1/16th to 1/8th from where it was. This makes sure the wick doesn't get pinched. Or you could cut the plug if you like more work. The result is the same.
Done. Now I can use any juice and not worry about any burning. This thing vapes excellent. I never get any juice in my mouth because all the seals are where they were. No leaking at all, even overnight sideways.
FYI I tried other methods, and it was a ..... for me to get the silicone plug out, and I wanted to be able to dissasemble it anyways.
Do to thick juice, I personally hold it upside down every 2 vapes or so, just to make sure that juice goes to the wicks next to the coil.
None of this is required, but it will certainly perform better.