I switched from Camels to e-cigs five or six years ago... that made a
huge difference to my lungs. Still less than ideal, but better.
Last summer I started reducing the nicotine in my juice and by October I was at zero nicotine; at that point the whole vape thing was distinctly unsatisfying and I was able to toss the whole rig after about two days. Haven't looked back since.
There's the occasional moments where a smoke crosses my mind. But they're very specific situations and it's pretty easy to disregard the momentary cravings now.
I'm sure my cycling will forever suffer -- at least somewhat -- from my 25 years at a pack a day and my several years of vape juice. But I'm definitely better off than I used to be. And for the record, I'll wholeheartedly endorse vapes over cigs if you hit a point where you
must have nicotine. Sure, they're not proven harmless and probably aren't; but cigs
are proven lethal and I'll take a "maybe" over a "for sure" in that category any day.
Good luck and don't quit quitting.