The Protank is using a wick versus filler, so it would be considered a clearomizer, maybe super clearomizer! My favorite RY4 loses much of it's flavor in cartos, and they don't handle 60/40 juice very well, gunking up rather quickly. In terms of flavor and vapor production as well as longer useful life, I find clearos far better than cartos. They give a genuine flavor much closer to dripping than anything else I've used.