I am only a few days in. First PV came on Wednesday. I've had about 8 cigarettes since then and none since the half one I had yesterday morning. I was a pack+ a day smoker and had a horrible hacking cough. I already notice a huge difference. I can take a DEEP breath w/o wheezing and not have rattling in my chest. I think this is the first time I've gone more than 24hours w/o a cigarette since before I was old enough to drive.