Just skimmed through the topic.
By what I've read these things sound better for you then normal cigarettes. If I read it right they cost less and contain less of the chemicals in normal cigarettes. Also no second hand smoke. If you absolutely can't quit; how are these a bad alternative choice?
They contain higher doses of nicotine which will probably addict you more. Some companies sell cartridges with less nicotine (maybe), but there is also non-nicotine ones with only flavour if you don't want the nicotine (which is kind of silly). I'm sure you can find other companies that sell lower does cartridges.
They haven't even been tested for it, and aren't really an accepted method. It's better to just quit than use these, but if you want to smoke, and can't quit (SOMEHOW), then these are a good substitute