I actually do have both. I started with a Vamo...it worked. It kinda still works after screwing on an adapter hoping the one remaining thread would bite enough to hold said adapter....it held. That means I can continue screwing 510 devices to my Vamo. In the event I mess up the threads on my ProVari, I dont need an adapter....they'll fix it for me and they'll do it quickly. They won't have to though. Provape was thoughtful enough to use a hard metal that would put up with the abuse a chronic flavor changer can give a PV. My threads are as tight and clean as they were the day I got it. If I break anything on my ProVari, they'll fix it. Usually for free unless I really hammered it, in which case they'll fix it for an extremely reasonable price. There's no sense trying to knock ProVari. They got it right. Anyone who has one knows it. Most folks who don't have one know it too but it would be too humbling to admit and it would take half the fun out of ECF. The debates are a blast!
That being said, I don't knock Vamo. They work, they're affordable, they look ok, they're versatile...they have VW if you're into that feature for whatever reason. If you're buying a Vamo, you'll get a solid device for the money. If you have 30-40 dollars to spend on a PV, the Vamo is probably the way to go. By NO means is it a 30-40 dollar ProVari though. I had all kinds of doubts when I bought my first ProVari...they're expensive...is it worth it....I could buy 4 or 5 Vamos...blah blah blah. After using it for a very short while, all doubt was removed. They're worth every penny if thats what you want. To say a Vamo does everything a ProVari does...true. They both heat e liquid. But so does a Bic lighter. I choose not to use a Bic Lighter to vape.