Went through this in the last two months. I was a 1 or 2 cig a day guy, but full time on weekends. Thought I would give them a shot.
I started ordering disposable ones online (white cloud flings), and they were decent, but I wanted a bit more - including knowledge that the liquid was mixed here in North America.
From there I got the eRoll, which is a small ecig that provides good plumes of smoke in a small package that can fake as a cig. I use it still when I decide I am going to "vape" at work or around people - as its form factor is more socially acceptable. I just stand with the smokers. But while it is a great format, the mini tanks are a bit of a pain/finicky.
So I then got an Innokin iTaste VV3 (a variable wattage battery, which I understand to be a good feature for those that want to try juices at different heats) and the Kanger Aerotank Mini. This has slowly replaced my eRoll as my preferred tool.
Then this week I got a mechanical mod and watched vids to build microcoils. Basically these are just a collectors move, they look cooler and do provide more flavour and clouds.
Since trying them out, the cig spell has been very broken. Do I look like a ######? Yes. But don't care. I still have the odd real smoke at the cottage, but nothing like before, and it is never as nice as it once was. I also have seen my circulation return, smell return, etc. - and it has been surprisingly easy.
I would recommend you go to a local vape store. They can set you up with a starter kit and more importantly they should be able to let you sit down and sample a bunch of flavours. If you go for an eRoll at some point, I would keep the nicotine levels quite high (18 to 24 mg), while I will use 12-18 for my iTaste, and max 12 for my mod. Don't worry about going too high, as the delivery of nicotine in vapour is much slower than smoke. You (fortunately or unfortunately) will likely never get the full "1st of the day" nicotine rush that you used to with real cigs. Instead it will just make the vapour harsh on your throat.
Are there more studies required? Yes. Are the 4 ingredients in ecigs well known? Yes. Is breathing air better for you than vaping? Yes.
I am happy trading the 4000 chemicals in cigs which contain over 40 known carcinogenic compounds and 400 other toxins (including tar, arsenic, formaldehyde, cyanide, and ammonia) for the 4 in e-cigs.
But I do agree, we shouldn't be vaping in closed public spaces. Why? Because it is rude. Like farts.