I have used Prebuilt coils in a number of Atty's. To me SS simply Sucks! Yet, every company has moved away from NI200. What the hell is up with this? I need a serious tank with NI200 coils. Some are only Kanthal now. On that note what is up with TC now? This is bullshit to me. I had a great vape going until these bastards killed it. I doubt it is health. Do the Chinese care about our health?. Fuck, I would think if it was not for our money they would kiss our asses goodbye.