My only problem with the vmax is that the math is wrong. Not just wrong but, wrong Wrong WRONG. I have verified the output of my provari with a multimeter, what you set is what you get. I know, from experience, what wattage I like to vape at, the one time I tried a vmax, I set the voltage by doing the math on my phones calculator, plugged the exact same tank as I had on my provari set to the exact same wattage and got burnt, nasty, horrible hits. I will freely admit that I did not run tests on the vmax, but from personal experience it just doesn't do what it says it is doing when it comes to voltage. In my opinion, the current ranking kings of the vaping world are the provari, the darwin(if you can actually buy one and live with its IMHO ugly as sin design), the variable voltage reo, and any solid mechanical mod(like the silver bullet) with a kick and a kick extension sleeve. The only problem with a kicked mechanical is the difficulty of adjusting the wattage on the fly. As the owner of a Provari, the only one I'd consider buying in addition to it is the VV reo. That said, if the difference in cost is a real world concern for you, the vmax usually performs fine. Just don't think that any experience with it will translate to another device, as the voltage it is telling you is WRONG.