I've been vaping 100% since January and loving it. But I'm a little concerned about polyfill. I know the bad taste of a dry cart. It reminds me of lighting the wrong end of an analog. However when I get about halfway thru a cart and the taste begins to very slightly change, I worry that I'm inhaling burning polyfill and whatever chemicals or substance this synthetic material is made of. So I wind up tossing a cart sooner than later. I notice this with tobacco flavors mostly. I guess the sweetness of a raspberry cart masks this effect. I sometimes think I'm trading the tar and chemicals in analogs for for some nasties that the polyfill is made of. Any thoughts on this greatly appreciated. On a related subject, I've heard about tanks with no polyfill but the reviews are not that good. Anyone tried these?