30 year, pad + smoker.
Quit on June 11, 2014. Exclusive vaping since then. Also since that date, I've managed to lose around 40 lbs. I wouldn't say vaping is directly responsible for the weight loss, but I think that in helping me to quit smoking, it gave me the wherewithal to tend to my food intake as well. Smoking was causing me loads of mental anguish...I was really resigned to being powerless over it. Beating it has given me the ambition to improve other areas of my life as well.
Anyway...
Noticed improvements:
Chronic cough is gone.
Morning wheezing is gone.
Constantly clearing my throat is gone.
Ear/nose/throat related illnesses (sore throat/common cold variety) which plagued me when smoking are gone.
My voice is a lot healthier sounding (say those who hear it constantly).
Strange, unsettling sensations in my chest (not strong enough to be called pain, but nevertheless discomforting) have diminished. I still feel occasional tightness in my upper chest, but when I 'pop' my breastbone, it goes away. I think it's stress/muscle related.
I still get an occasional (painful) leg or foot muscle cramp, but nowhere near as many as I used to. When I do get them, the pain is far less intense. I drink a lot more water now than I used to, I think that has a lot to do with it.
Used to get winded just walking across the street to buy cigs

. Now walking, uphill, downhill, stairs, whatever, is no issue. Also, I can run again. I mean, I can sprint for a block with my dog and actually keep up with her, and I actually feel good after. When I smoked, I wouldn't even consider running unless it was for my life.
I think losing the weight was key to the more cardiac-related improvements. Hauling around that 40 extra lbs. AND smoking was just killing me.