I guess I don't get the whole VW thing.
The only benefit (IMO) is not having to do math if you want to dial in a specific wattage. Also, the resistance of your coil will change as it ages, so the VW mod will automatically adjust your voltage to maintain the desired wattage when the resistance of the coil changes, or when you swap toppers / atomizers.
The trade off, at least with every VW mod I've ever used, is there's a brief pause between pushing the power button and the atomizer firing. I assume this is so the mod can determine the resistance of the coil and dial in the specific voltage before it fires. I personally prefer the instant firing of the Provari, but this pause may not be typical of higher end VW mods.