As a non-smoking smoker. OR a Smoker that Vapes, Nicotine delivered in the dosage I prefer is WHY I vape. Yes I use the same amount of nic withing 2 points, with every bottle of juice. I only drop the mg/ml when I am vaping at higher than normal wattage, lower ohms, in my case.
For me, vaping non nic would be like drinking non-alcohol Vodka. I don't personally understand why one would do that. Same goes for vaping.