Ya ok makes sense. I'm good at talking out of my butPerhaps a difference in regulation method can cause the difference in performance. I know there is a subjective difference between my provari at 3.3 and an ego at 3.3
My guess would be the accuracy of the voltage reading. Also the eGo is suppose to be 3.3v but could have some variance. To compare apples to apples, you would need an accurate meter to verify voltage at the 510 on both. Also there can be variance in the 510 connection on the PV. What kind of metal is it. How well does it seat. This is because you can introduce additional resistance based on the physical connection. Many many factors, but step up, step down or PWM just supply a specific voltage.
Sev