E-cigs vs. regular cigarettes, what are the differences?

Less "tars": Some e-cigarettes have filtering functions that allow you to cut back on the nicotine in the smoke, and others do not. E-cigarettes deliver the same amount of nicotine, which is what is bad for your heart, but has less in the way of tars, which is what causes cancer of the mouth throat, and lung. There is no research i know of on the additives, flavors, oils and gases in e-cigs so we don't know.