Hiya mayummo
The ego-c is most like your tornado tank. The difference being that instead of changing the whole
atty, it would only be an atty head needs replacing.
The torpedo is Variable voltage device with a clearomiser.
Now it depends on what you're really looking for, and only you can answer that. We can all say what we
prefer, but only you can make that final decision

Personally out of the 2, I prefer the ego-c for pure simplicity. Its very easy to use and maintain, no fuss and
no mess filling (you're already used to filling tanks

) The flavour I believe is better than the tornado tank,
and the vapour it produces is great too.