+1 for the Darwin. I have both the ProVari and the Darwin and settled on the Darwin for everyday use (100% VG). On top of what wv2win has already mentioned, it's got a visual battery indicator on the (more detailed) LCD display, mini-USB charging port, transferable warranty (ProVape's warranty doesn't transfer, AFAIK), current limit is around 3 amps vs the ProVari's 2 amp (think dual/triple coil cartos), and only one button press or wheel scroll to do anything; check ohms, voltage, amps, adjust wattage, etc. The only thing that took me a little getting used to was the shape, but for me that turned out to be a non-issue.
That reminds me, let me respectfully disagree with the premise that the Darwin is "more expensive"... the Darwin is $229 for mod with internal battery and charger vs $159 for the ProVari mod alone. If you go ProVari you'll probably want the 18650 battery (which would be almost comparable to the Darwin's) then add $24 for the extension cap. Add at least two batteries ($24), plus the $25 charger and you're up to roughly $232 at ProVape. So to compare apples to apples (mod, charger and batts), the Darwin and ProVari are about equal price-wise for what you need to get started.
I thought the same thing at first, but someone here posted pics of the inside. The brass swivel connector looks like a barbell. One half being inside the mod, the other half outside. It's actually huge and would be really tough to break. Any fall that could break it would probably break any mod, but of course that's just my opinion. I'm not saying the Darwin is more durable, but I'm not as scared of the swivel part breaking anymore. I actually think they're about even, both solid mods.
Instead of being voltage (volts) regulated, the Darwin is power (watts) regulated. Once you set the wattage output with the scroll wheel, no matter what you put on there, a LR/SR/HV atty, carto, tank, etc; the power output (heat output, warmth, vape, whatever you want to call it) will be the same. If the resistance changes, the Darwin adjusts the voltage to compensate therefore keeping the wattage consistent. It's just a different way to try and achieve a consistent vape.
Despite sounding like I'm 100% in the Darwin camp, remember I have both and I think either mod would work fine for you. My wife loves her ProVari and wouldn't trade it for anything, but she admits the only reason she doesn't have a Darwin is because she prefers the tube style mod. Anyway, just wanted you to have a little more information that will hopefully help you decide. Good luck!