I have both, and there are no regrets either way.
I have (2) two eVics now going on to 1,500 hours each without a hitch, and have more than proven themselves to me. If you are an 11 watt+ vaper, go with the Provari. Below that, they perform equally well. If you'll use dual coil cartos or RBAs with 30ga wire with the eVic, I suggest swapping out the OEM battery with an AW IMR one. I doubt anyone can really go wrong with any of the major APVs such as the Vamo, ZMax, eVic, Provari, etc. as they all work rather well and do the trick.
There are characteristics and qualities which separate each out, and you'll have to decide what's best for you. I find Youtube videos do "generally" quite well to lay it all out on the table, since I'm more interested in demonstrable facts than people's opinions.