that it (I love this one) makes the vapor taste better than other devices at the same power, including the mvp and mechs. They talk too much about the warranty, which is frankly a joke, and trash all other devices.
to be fair, there is some honesty to the taste thing. it can be highly dependent on the topper, though.
for example, if you watch PBusardo reviews, he graphs the outputs on an oscilloscope. the 0-scope shows that the prothingy and the mvp have near flat signals and that the prothingy outputs the voltage it's set at whereas the mvp tends to often output ~0.2V under it's setting.
now, of course someone could simply raise the output of the mvp by 0.2V in relation to the prothingy, so, meh... for the price difference it's your call as to what's important to you.
but when compared to 33Hz mods, there is a difference. this is where the atty of choice plays a big role. if you're using a rebuildable with .30 gauge, .28 gauge, etc. kanthal or the likes, then there isn't going to be a difference that's worth noting. but if you like to use cartos... especially in tanks... then it's going to be easy to notice that the 6V output over heats the coil, pulses and cools at an audible tone. this means not only can you burn your juice at the same setting as you'd enjoy on an mvp or prothingy with a steadier output, but while it's burning you hear the tone and it can irritate the bejeebus out of you.
not that an 800Hz signal doesn't make an audible hiss, but it's not the double whammy of "the rattlesnake".
and i will concur that the warranty and warranty service is second to none. they give clear, explicit instructions, fix and return your product promptly and when i returned my wifes prothingy for service, they returned it with a little thank you prize. so obviously, they're not completely void of fault. the display on hers went awry and with only one digit, you can't exactly change settings. but it was returned to use less than a week after they received it and she got a free carto tank, drip tip and carto for our troubles.
so obviously i have a provari. i will likely be selling it for a reason, too. i like less hassle than most toppers on the market these days provide and more power and better taste than i'm going to get on the provari. i want to talk the wife out of hers in favor of a Reo Grand also.
but all in all, it is a great, sturdy, reliable product backed by a company who cares about their customers and their reputation. what's not to like?
that's not to say that i think it's any better than say a semovar and obviously it's not going to hold a candle to a dna mod, but you'll be hard pressed to find a 15W variable mod with better performance, reliability, ruggedness, accuracy and a better company backing it.