I will just add this; while on vacation a couple of weeks ago at an all inclusive resort down south, I ran across a guy at the pool bar who was bumming a cigarette off someone and he said: "The vaping is OK most of the time but after a few drinks, I need the real thing!"
Now, I have no idea whether he was vaping stuff with nicotine in it or not or how long he'd been vaping vs smoking cigarettes but clearly in his mind he was still "hooked" under certain circumstances. My own feeling about vaping is that it still keeps reinforcing the smoking motions and activity itself therefore, you're not retraining your brain to operate as a nonsmoker. Therefore, the danger of going back to the cigarettes is much more real and likely at some point. (my opinion only - not scientifically based).
I'm just glad to be done with it all and yes, cold turkey was not a lot of fun but for me, it was the fastest and cleanest way to get away from this addiction and start retraining my brain how to life without smoking anything. I'm mostly there now and feel I will be on track to stay permanently quit by the time my 1 year anniversary rolls around. Still a little minor work to do here and there although it's pretty light stuff now compared to early on in the quit :)