I looked at Provari and Darwin back in Feb when I was VV/VW shopping, ended up going with a Notcigs Infinity, and recently picked up their Buzz Pro (Infinity is still going strong).
I run all day, 6 ml consistently, on one set of batteries, with either the Infinity or BP, typically at about 5V/8W use; I don't sweat the battery charge level -- it lasts me until the end of the day, when I swap batteries. The durability of the Notcigs products is well known -- they stand up well to a lot of abuse (in my case a bunch of drops onto hard concrete, over months, and the finish is still clean and they work well; others have had Buzz drops of up to 25', and gone flying at 60 mph

)
Base Provari run time was a bit iffy, from things I've read here on ECF, though with the new battery that should have gone away as a weakness.
Weight-wise, from what I've heard the Buzz is a decent amount lighter.
LCD (Provari) vs. single wheel adjustment (BuzzPro, Infinity, soon to be released Infinity Pro) is highly subjective. I don't particularly care about reading the precise number, I rotate the wheel to taste, and preferred not having another failure mechanism. I've never had the voltage wheel accidentally change on me.
The BP has a positive off, to prevent misfiring. A new end cap has a non-conductive section, so unscrewing it slightly disconnects the circuit.
Price-wise the Buzz is a decent amount less expensive, if you kit them similarly (couple batteries/sets each, charger, base unit, extender cap for the Provari.). The new Infinity Pro should be yet another $40 less.
I actually am an electrical engineer by trade, but when I vape I don't particularly want to think about the volts, ohms, amps. I've spot-checked resistance on a carto, or an iffy battery, but it's not something I do every day (or every month, for that matter).
Provari is absolutely an excellent PV, many people enjoy them a great deal. If you are into the tech side of vaping, it's a super device. If you prefer simple, the Buzz Pro is great
