I actually prefer going down the "factual" route as opposed to "adversarial" route.
I've owned a couple of Provari's and owned a Vamo.
Both the Provari's I've owned have been rock solid, the build quality is unrivaled and they are dependable to an extreme degree.
The flat regulated output of the Provari gives a top notch and smooth vape.
The Vamo is also a good
device but the build quality is lacking as is it's reliability, it's a good
device for the money but it's somewhat disposable.
The Variable wattage feature is not actually as precise as the voltage feature because of the .5 increments, it obviously doesn't take into account the fact that various devices behave completely differently at the same wattage.
I've also experienced voltage "spikes" on the Vamo that can pop a coil - the Provari doesn't do this.
If you want a device that won't let you down in your quest to stay off Cigarettes then the Provari is it.
If it's a backup you're looking for then a Vamo is for you, I'd never own a single Vamo as I've seen way too many broken copies.