Didn't know what else to call it. I have no idea who started calling these 'regulated', quite simply they are not. You can't 3.7V regulate a single 3.7V Li-Ion, unless you add a booster to it, like in the ProVari. The vaping voltage will in fact drop a bit with each drag, that's how cells work.
These PVs also have more resistance than a well built naked 18650 mod due to the switch electronics and the extremely thin, thread-like wiring they use. That also influences the initial voltage, drop while vaping, and vape times.