I own Provari, Vamo, Ego and several mechanicals, with Protanks, various attys that use Protank heads, and a double handful of RBAs. They each have their ups and downs.
The Vamo will not operate below 1.2 Ohms. However it's chip allows me to test coils/batteries extremely fast with a single button press, and surprisingly it has lasted me more than half a year. So not too bad a $25 investment. It's 510 socket is junk, so I popped on a permanent airflow control adapter with stainless threads.
The mechanicals are tough. Pretty much indestructible tough, especially the brass Sentinels. Fire every time, consistently, and heavy enough to let you know you have something solid in your fist. But if you don't pay attention to what you are doing with the coils and batteries you could end up with a mini-pipe bomb hanging out of your mouth. Still, they are one of my main grab-n-go devices for daily use, and if I feel like vaping .6 ohm they will do it all day long without complaining.
The Provari slowly replaced the Sentinels as my main vape but it was far from an instant switch, and it wasn't until I bought a couple of Tatroe rings so I could use my 18650 batteries that it started to grow on me as far as a daily carry to work device. Yes it's vape is much smoother than the Vamo. It also will work at less than 1 ohm, unlike the Vamo. The lack of VW is irrelevant. A VV/VW does one or the other, but never BOTH at the same time, and they equate to the same thing seen from opposite ends - keeping the same voltage automatically changes the wattage, or keeping the same wattage automatically changes the voltage. The Provari keeps the voltage you set it to, so it changes the wattage automatically.
The Provari does have it's drawbacks. It's electronics are great for smooth vapes. Ok. They are bad for speed of display/changing settings. Let me elaborate with one example:
Powering On from being turned Off:
Vamo: hit fire button 5x fast. Vape
Provari: Hit fire button 9x, wait for display to read Po then Of. Hit fire button once again to change Of to On, wait for LED to go out. Vape.
I have devices that cost $10 and I have devices that cost $200. All are able to produce a great vape with the right choice of toppers and coils, and in their own select little niches they perform very well. If I had to choose only one device as the only thing I could ever use to vape on ever again, I would probably choose the Provari, not only because of the smoothness of the vape, but because it can reach lower ohms than the Vamo while being nearly as durable as the mechanicals. But I would also gripe a little bit at how long it would take to check a coil's resistance on it. Still, all in all, it combines enough features of both a VV/VW and a mech that it bridges the 2 extremes nicely.
Then again, a device is only as good as what you put on top of it, and if your atty is junk then a Provari, REO or DNA is not going to magically heal it's flaws for you. Junk is still junk and these devices are still little more than fancy battery holders. But as part of the whole set they will not let you down and if you want a smooth vape then the Provari is worth the money just like your analogs were worth the $5.50 a pack day in day out for how long?....