Hmmm...almost vaping for 3 years (began in 2010) and as far as health? Well, as much as I would love to show you my before and after pictures (no way and hell would I, though it is great for fitness forums), I will just say that I began working out, eating right, and just caring bout my body altogether after I stopped smoking--it would seem that when I smoked, I just didn't give a spit about my body. My cardiovascular endurance, strength, LBM (lean body mass) and overall physical well being pretty much skyrocketed. Now, I would be remiss if I didn't add that vaping also brought about the end of a couple other less than positive, uhh, activities as well--once I didn't smoke, that other stuff went away (thank GAWD!). It would seem as if smoking was, maybe not a gateway, but it sure as hell kept the door open for the other madness.
All that said, I don't have the lung capacity that I would like (though it is tremendously better than it was), and that is likely do to heavy VG vaping, but the doctor says that I am all good and I feel pretty damn good. Maybe I occasionally get a little congestion, but I can't say for sure what that's from.
If you stopped smoking, irrespective of whether or not you vape, you will feel and be better; if you vape, but no longer smoke, well, you no longer smoke, so back to the original point. Vaping in and of itself is not healthy per se, but it is not what one would consider "unhealthy" either.