I have istick 20w, and i've been researching about sub-ohm and wanted to get subtank nano with 1.2ohm coils for it. But wanted to know if sub-ohm is worth the upgrade to try out 0.5ohm subtank as well as eleaf melo. I'm a fan of organic cotton, currenty running evod micro coild on my evod with japanese organic cotton and its very nice. Maybe should i wait for dna 40 temp regulated mods to come out?