Main consideration was price but if there is a reason to step up to the ProVari I just may do it in the future.
The only thing I don't absolutely love about my ProVari is that the extension endcap for 18650 batteries doesn't look as cool as the original one for 18490; I find that the 18490 is not an all day vape for me, so I'll mostly stuck with the extension cap on
Other than that, a ProVari is just a joy to hold and to use all around.
It's fantastically consistent - Phil Busardo caught it in the act: he managed to measure the voltage output on the very last button push, as the battery was dying, and it was spot on. That is something you feel in the vape - every single one is identical to the previous one, throughout the day, until it starts blinking.
It's heavy, but in a nice way - it feels solid, reliable. My satin black, at least, is almost sticky - you can't get it to slide no matter how soft you grasp it. The button is in the exactly right place. It doesn't click, but it gives you a clear feedback, soft but consistent, and it sort of springs back when you stop pushing it, slightly pushing against you finger so you don't ever get to be "neither on nor off".. it's hard to explain.
The current amperage limit is above anything I could reasonably need. I can use it to get all the power I, at least, can handle out of anything I put on it. As a bonus, it functions as a meter for the battery and for the carto/atty resistance. It's everything.
Again, it feels, at least, durable and strong, carefully crafted. There's no give, no jiggle, no squeaking threads.
It has a deep drip well.
It gives you all the peace of mind you may need - safer chem batteries running on a smart circuit that constantly monitors voltage, amperage and temperature. It doesn't let you do unreasonable things, and it tells you so by means of error messages (unlike the VZ VV/Lavatube).
You have 0.1 V control - I didn't think I'd care much about that, but in using it you discover that subtle adjustments go a long way for some carto/juice combinations.
Did I mention how solidly built it is?
I guess, as a purchase, you can actually tell where the money went with every vape you take. Once you hold it and you vape it, it doesn't seem expensive any more.