Love the Darwin.
I live in a USB world and it's nice to not have to mess with maintaining/changing batteries.
I grab the unit and go.......
The variable wattage feature is really nice.
Love the swinging arm. It makes the unit very ergonomic because it allows you a huge range in which direction you point the atomizer. When set from 90 to 120 degrees it also turns the Darwin into a great platform for tanks and one handed dripping.
Darwin is a very 'Green' device. The batteries in it are small and light. You don't need a bunch of extra stuff to charge and maintain them. They are rated for up to more than 4 times the number of charges as a regular 18490/500/650 type battery. The batteries are guaranteed by Evolv for a year.
Unless you already have chargers and batteries laying around, the price is about equal to other PVs decked out to match its performance.
If you can find one...grab it. Don't like it? You won't have much problem getting most if not all of your money back