Provari does a lot more then just change voltage...it has a built in safety system for bad batteries and dumb user errors(like putting an LR atty while its set at 5.7V, mod wont fire so you wont kill your atty), checks your attys resistance in case you dont know, and check how much power is left in your battery.
Plus it has the LED screen that actually shows you all this info...some of the other VV's do none of the above, some only do a few And your guessing or having to pull out a multimeter to check voltage(PITA IMHO). (Darwin is the only other VV that does all that I believe though I may be wrong stuff changes. but that is why those to are more $$)
Why are not all mod VV...
VV is still a pretty new technology to ecig mods, and the chips making VV possible arnt that small and take up room inside the mod not all mods have the room to be adapted. Just for example in the provari the first two inches of the mod...is the chip and regulators, where my GLV SM..the entire length of the mod is about two inches So it wouldnt fit in there.
Plus not everyone feels the Need for it...plenty of folks are happy with their 3.7, 5 or 6v.
Also VV users will tell you...lot of em basically set their voltage and go with it. Not like it's in constant up n down use. Keep mine with a 510 carto at 5.2 basically all the time lol.
Changing between voltage on none VV mods..yes you change out the batteries. Like going from 2 16340s(6vs) to one 18650(3.7v). But only some mods can do this. Not all of them can accommodate different types of batteries.
Why not stick with eGo's..
There is a pretty big difference between 3.2 and 3.7...believe it or not. Plus being used to an eGoT...3.7 with a LR atty would be a massive difference. Those Tanks dont hit anywhere near as hard as attys let alone an LR.
AND personally what drove me into mods was the cost of batteries. All Batteries die..just a fact, they can only be recharged so often. eGos are around 10-15.00 a battery...mod batteries are 2 to 10.00 a battery.
Tank cartos/tank mods there is a hole that a 510 drip tip will fit into for the mouth piece, if it doesnt include one already like the lava tanks.
lol did I get it all?