joyetech penguin is a really good choice for advanced vapers - not just an ecig, but as well a dry leaf and vax vaporixer. This top tc mod works like a beast - so much vapor and such a long battery life. This is a bit more advanced technology - they are using mini-tanks and you can see how much liquid is there left in the cart. On the battery you can see how much power it has left. Vapor amount of nitecore sc4 superb charger is amazing, flavors are great. Price is a bit high though.