THe people who say it doesn't work didn't actually experiment to get the right blend. Like seriously, how many different brands and types of cigs have you tried to get your favorite? When you first start anything will do, but after years of smoking you KNOW you have that prefered blend. Just like beer. Vaping is the same, and it's a huge ballpark to get into. Nicotine levels, flavors, and how it's administered all make a difference. Nicotine and power (voltage) depict how hard the "hit" is which is what most smokers are looking for. My mom smoked all her life and now literally chokes on my hit because ecigs have weaned her off nicotine completely. She was also a chain smoker of menthol Marlboros.
Nicotine isn't a hard drug to get off of. I smoke with 6mg in my mod and can quit at any time. Wash my tanks, toss my bottles of fluid and stay off as long as I want to. What you can't quit is the habit, and unfortunately the older you are the harder a habit is to break.
In comparison to vaping and cigs, how many harsh chemicals are in cigs? Well, let's see, one being tar. Yea, they make roads with that ****. The only thing people have to argue on vaping is glycol, but it's food grade glycol being used. Anything you inhale is not going to particularly be good for you, but there are literally countless people who will admit how much better they feel after moving to vaping for at least 2 weeks solid. That says something right there. Now add on, the **** doesn't stink, doesn't produce a nasty second hand smoke, doesn't stain anything, doesn't linger, tastes good (depending on the flavor of your choice), and to some more importantly is way cheaper.