For what it's worth, I have both a Provari and a Vamo, and... well, it's pretty much indisputable the Provari's built better. That's obvious within a few seconds of messing with them. Is the Vamo built badly? No. But the Provari's a pretty tight piece of work, and sets the bar pretty high.
But, yeah, the Vamo has VW... and except for playing with it a bit when I first got it, I don't use it. I like adjusting things for which atty I'm using, the type of juice I'm vaping, etc. VW provides some consistency across those, but I've discovered that I don't really want consistency. I just get a better vape without it.
So, yeah, the Provari's just a better machine. Worth the extra price? That's really up to whoever's thinking about buying it, really. Personally, I prefer the Provari, but that's mostly because I'm clumsy and I really don't think I could break it without trying really hard. I'm not sure I could say the same for my Vamo.
The Provari's a bit smaller in its all-day battery config, too, which is nice, and I love my Z-Atty-Pro, wbich just happens to work better on the Provari, so there you go.