No leakage in this new Melo 4. E-leaf has finally figured it out. The design ensures a tight seamless fit of coil and tank. The only problem is high VG juices don't tend to wick properly so you might have to poke a hole in the cotton with a needle which is more common practice than you'd think. I'd imagine a 50/50 juice would wick just fine. I bought a bottle of 50/50 today and am getting tons of flavor at a low wattage. My first glass piece broke on me fairly easily tho so do not drop. Although the replacement glass was under 4 dollars. In a pinch or for beginners you can't go wrong for 23 dollars just make sure you buy the proper juice for these small coils. New ec2 coils are out and they're pretty good.