I smoked between 40 and 60 Gauloise a day for 36 years. I had difficulty breathing, especially at night, and colds that would last for weeks into months. On 2 June 2014 I bought a Twisp and have not touched a cigarette since that day. That makes it over 6 years. During that time and according to an app I use, I have not smoked 88,783 cigarettes and not spent R173,128 on smoking.
It has transformed my life. My sense of taste returned after about 2 weeks, breathing is normal now, sinus and colds are rare (every 2 years) events and last days. I have, over the years, got into DIY and have cut down my nicotine from 18mg to 0,1mg. Vaping simply saved my life.