I am also impressed. If I can get 15-20ml out of a coil that's a deal to me. I think people in general are asking kind of a lot from these heads. I mean, I would have to rewick my kayfun and Erl every 10-15ml, somtimes sooner. Drippers get rewicked once a day... I really think people are asking for something that cant be done with known technology. If you can get 20+ml through anything other than a genny with mesh without rewicking, I'd love to see it..