I've had my Darwin for a couple months, now, and I love it. It is not, however, an unconditional love. This is an ingenious device that could stand several improvements.
1. Please make it stop: My Darwin has a nervous tic. Every six seconds it is compelled to wink at me. This would be tolerable except for the fact that when any other PV flashes it means "PAY ATTENTION!". Sometimes, "PAY ATTENTION AND COUNT!". I know this is normal operation for my Darwin and, after several months of use, I can mostly ignore it. Every once in a while, though, I still catch it winking out of the corner of my eye and I PAY ATTENTION! ...this is annoying.
2. Get a grip: This is a well-made, solid, heavy-ish device. It would be good if the handling end weren't so slick. A knurled texture along the sides and bottom of the device would make it easier to grip. I'd even buy a good 3rd-party-designed neoprene sleeve for this thing (think ipod case). Anybody wanna make a Darwin wetsuit (or glove)?
3. Harden it: Brass is very pretty but perhaps not the best material for a rotating, threaded atomizer connection. As elegant a design idea as this is, and I really admire it, brass is relatively soft stuff. The fragility of the threads has been side-stepped by the inclusion of a 510->510 extender (for Nhaler purchases). I personally prefer a small goose-neck (allowing the device to "close" with a tank attached) but it is just unwise to attach your cartos and attys directly to the Darwin if you swap them out more than a few times a day. Is there an equally beautiful but more durable material that won't ridiculously increase manufacturing costs?
4. Weebles wobble, but atomizers?: I like the way the connector "snaps" firm at the fully extended 180 degrees. I find, however, that I more often vape my Darwin at 135 or 90 degrees of rotation. ...where my rig wobbles a little. Having "snap" positions here AND having it "snap" closed would be truly excellent.
This is a brilliant device and my favorite PV by far. I'm certain I'll get at least the warranted 2 years of happy service from it. Address any two or more of the above criticisms and I'll buy another one in a heartbeat.
I'm sure this stuff has been mentioned before but, damn the redundancy, I am MUCH too lazy to read this entire thread.