Dovpo MVV is capable of 1V-8V whereas NC2 is capable of 2V-6V. I can't imagine ever needing/wanting to go above 5V myself but having that extra space on the lower side is useful, especially in the mornings when I feel dead. One problem though is that this does result in tiny movements of the potentiometer causing pretty large changes in wattage on low resistance builds. The Dovpo VEE has a screen and I think allows you to increase the voltage in 0.1V so presumably that allows for slightly more fine tuning.