Yup I've been vaping for 3 years and have not touched a single analogue cigarette or even thought about it since.
I smoked rollies (hand rolled fags) for 22 years and towards the end got to the point of coughing my guts up every morning and coughing fits throughout the day, it was horrible. Also I could tell my circulation was in trouble, so to ignore this would have been stupid.
When I decided to start vaping, first I tried those ego style variable voltage pen thingy's with a Nautilus mini and 18mg juice - did sort of work but weren't good enough.
Then bought a Solara DNA 30 box mod and some dripping atty's - quickly found out that nic needing dropping so dropped it to 10mg. Stuck with that for 1 year it was ok.
These days I've got 2 X DNA 200 box mods (VT200 and Volcano lavabox) and several rebuildable tanks, its so much better and I know what I'm doing. Been mixing my own e-juice for 2 years, make my own coils etc. Now down to only 3mg strength which is next to nothing nic wise and the flavour is so much better with lower nic levels. Normally I vape anything desert or fruity. At this moment I've got one mod with lemon coconut cream cake and the other mod with doughnut king, custard flavour is another favourite of mine.
If I had still been smoking analogue fags I would be in real trouble health wise or worse.... dead! So even though this (vaping) is still a habit it keeps us off the evil cigs and as far as I've noticed there have been no nasty side affects, my circulation is significantly better and I stopped coughing my guts up 2 weeks after giving up the evil cigs. All around health is tons better.
In rare cases some people have an allergy to Propylene Glycol (one of the components in e-juice) so they can get around this by using 100% VG juice. (Vegetable glycerine).