I currently have a iJust 2 I want to take a step up and get something better so I'm between an Atom Sub Ohm Revolver Kit a iSmoka iStick 100w mod Kit or a Kangertech NEBOX kit. They are all around $40 to $50 USD due to sales right now so which one would you recommend and why and also if there is a different kit for around $40 to $50 maybe even a bit more that's better please tell me thank you : 3