I have no earthly idea how anyone vapes at that power level; if I go over 9w with mine, it tastes burned. Probably just the juice I like, it's a very delicate taste and too much heat just ruins it completely, which is why I hate dual coils of any kind -- bottom coils, cartos, or even those dual topcoil iclear16's. Nasty.
I think maybe you could have burned it. I'm no expert, but it's kinda like, if you burn something in a stainless pain on the stove, you have to really work to get that burnt taste out of there; I always soak my stainless cookware in white vinegar, it cuts the starch/hard water gummy/hazy looking stuff off it, keeps it sparkling.
I have no idea if vaping is really analogous to cooking in stainless, but it just seems to stand to reason -- stainless, high heat, liquids, flavors... *shrug*
I'm very happy because I just got my quartz kit, so I get to finally taste this excellent Pineapple Express in a kayfun... can't wait!!!
Andria