Pretty sure I vape more than I smoked (and I still let myself have like 5 a day). I peaked in my smoking at around 1.5 ppd, quit, restarted (yada, yada...) and right before vaping was at about a pack. Even at my peak of smoking, I always felt like I was monitoring myself. The only time I consistently let myself chain-smoke was lunch hour (five or six--and I managed to eat as well).
Because I switch juice bottles, I don't have a good handle on how many ml I vape, but I'm going to guess 3-ish. My drive to work (before, two cigarettes over 40 minutes, now, vaping over the entire drive) says a lot. Then at least, I let myself vape as much as I wanted to smoke. I haven't taken the trouble to fool much with nic levels and pretty much stay in the 24-30 range, and I fairly often get borderline "nicked out" in ways I never did over decades of smoking. Probably a tad higher than where I ought to be, but that helps me either not smoke any number of cigarettes, or at least really not enjoy most of of those I still do. Except that first one in the a.m.