dreamflier,
I went on to e-cigarettes, at first it's comparable to going from a strong beer to a weak shandy but after the breaking-in period e-cigs became my norm and after 6 months of those I quit all together and haven't touched, nor wanted, a cigarette for the past two years or more.
As for e-smoking, indeed e-steaming, on flights it is one of those rules that cannot be enforced, e-cigarettes are literally odourless, one can cup the device in one's hand, take a puff and swallow the water vapour than one would otherwise exhale and without anyone around being any the wiser and the water vapour that these devices give off is never going to set off any smoke detector.
And e-cigarettes offer no harm to anyone, they merely contain nicotine and, to the best of my knowledge, nicotine has never harmed anybody, it's the other "nasties" in cigarettes that are the "killers".
I wouldn't encourage anybody to break any rules though, just merely pointing out the stupidity of such an unenforceable rule.