You can get a bit more nic, from the extra power. A decent HV or VV mod makes it like you are always using a straight pasthrough, lots of oomph.
I vaped 3 ml/day on either 808 or Riva 510 gear, very consistent. When I switched to a good VV mod I doubled eliquid consumption, 6 ml/day, again very consistent -- I carried a 6ml top-off bottle, I would just empty it at the end of the day, and refill it for the next day.
I stayed 24 mg/ml for several months on the VV, no problems, though in April I decided to start curtting my mg (just because I felt like I could, not from too much nic). Now, 7 months later, I'm using 15 mg/ml.
Another bump in intake happened when I got a good carto tank, though that was only for a few days, the novelty of continuosly getting an excellent vape, very few refills during a day. I'm now back at my consistent 6ml/day consumption -- twice what I used on 808 or Riva, but consistent since late Feb.