It boggles the mind, how many choices there are. And such a variety of opinions of what the right choices are!! Prior to January of 2015, I had a few hundred dollars invested in juices and devices. Since January 2015, I've invested close to a thousand dollars more...and I'm not finished yet!! The evolution from disposable cartridges to refillable cartridges to refillable tanks and replaceable coils to variable voltage to variable wattage to (now) temperature control and then onward to RDAs (isn't that backwards?) and then on to RTAs (RDAs with tanks) after I invested in RBAs (tanks with wicks)... I was staying away from Sub Ohm and then I heard about temp control...well, to do temp control means sub ohming, so there I went.... Now I am ready to rebuild and to leave the prebuilt behind.