I once measured the device in question (a Riva), and (not under load) it was putting out 3.5V and change. I've used different LR atties from different manufacturers, and there doesn't seem to be a consensus on what low means in terms of ohms. Bottom line, I've been on shifting sands.
Meanwhile, I've been shifting myself. I have to admit, after scraping my soul clean, that part of my motivation for vaping at 6V (whatever the wattage worked out to) was the fact that I could. It was a novelty. I was seduced by the creamy, super-abundant vapor; yeah, the flavors were saturated down to their socks, but those socks were singed around the edges.
These days, I've mellowed to a 18650 3.7V power source (it's more like 4.0V when fresh off the charger) and a standard atty.