The short answer is: NO.
E-cigs are a clean way to dispense nicotine to the body. Nicotine is not good. It raises blood pressure and depresses nerve transmission, and it is extremely addictive and produces cravings when not assumed anymore. In a hindsight, I would have never started to smoke. Is to be recognised that, seen the level of dependance caused by nicotine, it is almost impossible to quit without some assistance.
Smoking tobacco adds insult to injury, because you smoke to get some nicotine (and other substances of the same class and effect, like anabasine and myosmine which are also contained in tobacco plant), but you get something really not wanted, like carbon monoxyde and tar, plus hundreds of other contaminants, including heavy metals.
E-cig delivers only nicotine, assuming you use good quality e-liquids. Brand e-liquids are prepared with medicinal-grade polypropilene glycols and glicerine, which are mostly harmless. Somebody voiced the possibility that industrial-grade substances may end up in e-liquids since the very high markup they command; I have no info on this.
E-cigs are much much better than tobacco smoke, as you only get the nicotine; can say that they are useful in minimising the harm caused by nicotine assumption.
In no case e-cigs are healthy, as nicotine is not healthy. Even if - this is my personal opinion - the hunt for smokers is an unnecessarily punitive behavior proposed by society as a whole; nicotine is bad, but not so bad to warrant hiding cigarettes in stores, printing disgusting pictures on packets and pouches, and getting to the point of almost criminalise the gesture of bringing something to your mouth.
E-cigs are a very rational replacement to tobacco, as they minimise the harm of smoking. I'm grateful to have been given the possibility to switch from pipe to e-cig, and I am hungry to the stupidity and greed of those trying to remove this possibility to former tobacco smokers. As I am hungry at those manufacturers and sellers that compare the price of their stuff to tobacco products, drawing too many undue attentions to e-cigs: one EU Country, from January, is already taxing e-liquids just like tobacco, to say only one.
In the back of my head, there is a tought running... I need to quit. I quit tobacco with e-cigs, I can breath much much better, I gained more energy, and many other positive effects. I now switched from 2.4% to 1.8% e-liquid and felt the benefit.
I tried patches and gums but they don't work. E-cig does. Eventually, I may end up smoking zero-nicotine e-cig, as the gesture and smoke production remain very rewarding psycologically, and that will suffice to me.
Nicotine in e-cig is NOT healthy!