IMHO, and from the experience of many others, it seems 5V gives plenty of power and strength, even for a resistor of 2.4 Ohms. Also, you can get even more power by using a lower resistance resistor. Beside, I don't even vape at 5v most of the time because it has a tendency to get dry hits. Therefore, I don't see why some PV offer voltage at 6V or above. Can someone tell me the benefit of that? It seems to me all that power is an overkill when the wick has limitations on rate of juice replenishment, which can lead to dry hits. thanks