I don't own a Provari, but I did talk my buddy into getting one (so I can play with it too lol). I had an eVic (before I left it at a bar), I have a Vamo, a kick, and a slew of mechanical mods, along with countless ego style VV and non-VV batteries.
You don't get the Provari for its features, a $50 Vamo has you covered. You don't get it for the display, it's lacking. You don't get it for the battery config flexibility, also lacking and expensive to upgrade (relatively). You don't get it for "set it and forget it" as it's only VV. You don't get it for its "superior voltage regulation" as I couldn't taste a difference between it and my Vamo given the same voltage settings. You don't get it for battery life, as that extra bit of voltage regulation costs you some of that. Not to mention the lack of airflow slots in on top, which inhibits some atomizers from performing correctly. The Provari would seem to be quite lacking compared to today's less-expensive alternatives (but give it credit, it's been around a long while and was a very innovative product in the beginning).
You get it because it is rock solid, can be dropped multiple times, and has a 510 connection that won't strip out on you after a few months, especially if you use SS atty's. It's all about the quality of the device. I would have easily laid down another couple c-notes to get one had I not already discovered higher-end mech mods and the kick. It's a reliable, very well built device that won't need replacement 6 months down the road. My buddy has dropped his countless times, even broken off cartos inside the 510, and it performs flawlessly every time and the 510 connection threads flawlessly every time. You can only go through so many cheaply made mods, regardless of performance, before you finally give up and just get one.
Before I lost it, the eVic I had was already starting to strip out at the 510 after a month or so use of an AGA-T+. The Vamo I have now is almost useless due to a stripped out 510 connection. I also had to "ghetto rig" an o-ring where the original insulator used to be due to the original crapping out, causing the positive pin to sink down and barely make contact with my atty's. I do not miss the eVic, nor do I use my Vamo, now that I have a quality mech with a kick. And had I not already gotten into SLR and RBA's, I would have gotten a Provari in a heartbeat after having seen the use and abuse one can take.
I haven't read the whole thread, not going to, and the above has probably already been stated countless times. But I felt it's worth repeating.