So I've been vaping a couple months(got started with the ego one, which I like, started to quit smoking), and I want to get a box mod so I have more variety with tanks, rda's, etc.. I've been looking at TC mods because it seems to be all the rage now. The Evic VT looks amazing but I've read that a lot of people have issues with it. Are these rare occurrences or is the product defective?