Sector, I agree with you that in principle VW is a nice deal. I believe that the Vamo's processor is so inaccurate that the value of it on that device is quite questionable. I believe the eVic is a bit more accurate at sensing ohms, and delivering a voltage as indicated. But even with the eVic, when your Volts delivered exceed the volts of the battery, it begins to break down and is not as accurate. So even though both of these mods have a nice feature that does have some distinct advantages, their execution is so sloppy that they end up getting outperformed by the simple elegance of the ProVari.
All the ProVari does is deliver the exact voltage it indicates, with a smooth and consistent voltage, from the first puff to the last of the battery. There is no comparison on vape quality.
SO to go back to your AC thermostat analogy, you said the one with the stat was VW, and the one with the on/off switch was VV. Let's tweak that a bit. The VW is an AC with a digital stat, with night set back, schedule mode, and all sorts of features. The VV is an old bimetallic strip type deals. A round stat with an indicator arrow for set point, and a second one indicating actual temperature. Now the digital stat wins hands-down, right?
But let's assume for a minute that the digital one is sometimes "off" as much as ten percent. Even worse, sometimes it is ten percent high, and sometimes six percent low. We don't know what it is gonna do! The old stat, well it is dead-on accurate. So while it lacks any of the features of the other stat, it keeps the space much more predictably comfortable. It does it day in, and day out, never changing a bit and doing what it does with simpler, but much more precise technology.
That, my friend, describes the current VV/VW situation. Great idea, that VW. But none of the mods that employ it (that I have used) have the basics done well enough to really take advantage of it.