I received my MVP v2 yesterday. So far, I love it, but I quickly realized I have no idea how to use it. I know about variable voltage, as I've used the ego VV v1 and various twists, but I have no idea about the watttage. The owners manual was a joke, just about anyone could figure out how to charge it and so forth. I'm going to have to find so information on how to use this puppy correctly.
Just remember one thing, when you adjust voltage on a vv battery, you are actually adjusting the voltage so that you will have a specific wattage at the coil. If you have more than one clearomizer, you might notice when you change tanks, you have to retweak your voltage settings. This is because of variations of resistance between clearomizers.
Variable wattage allows you to set wattage to taste, and when you change tanks, the battery will sense the resistance on the new tank and adjust voltage automatically.
the MVP does both, but not at the same time. If it is in variable voltage mode. It will fire the set voltage every time irregardless of the resistance on the atomizer head. If it is in variable wattage mode, it will automatically adjust voltage to maintain a constant wattage.
I personally like variable wattage because I can switch tanks and get consistent vape quality without having to further adjust my battery.
Some people like variable voltage because they can 'fine tune' the voltage to the exact value they like.
The best example I heard is comparing vv and vw to transmission types.
If vv is a manual transmission, then vw is like an automatic. They both perform the same function, just do it in different ways.
If you push the U button and adjust for voltage, then the battery is in variable voltage mode and will stay in that mode until you press the p button.
If you push the P button and adjust for wattage, then the battery is in variable wattage mode and will stay in that mode until you press the u button.
For more details on the operation of the unit, you can check out the review I wrote for the MVP 2 here:
http://www.e-cigarette-forum.com/fo.../503162-innokin-mvp2-essential-vape-gear.html