Right of the gate: this is awesome but flawed, here are the flaws.
Least important, the door has plenty enough play to be annoying.
The main thing is changing the coil and coil installation sucks. On most aio devices its painless but here it rears an ugly head. The coil has the be threaded into a piece that serves two functions. Mainly battery contact but also airflow control.
Once you get the coil threaded to it you have to thread the coil into the pod and in doing so the airflow ring can spin off the oring it sits on. It can and will come off a little bit which prevents the coil from threading far enough into the the pod. I had to install it a few times before the device would read an atomizer - when the coil, pod, and afc, are all flush with each other.
It fires so so well once that annoying step is over. Button is great. Not topfill but easy to fill and doesn't leak at all. Coil life is good and flavor is good, maybe a half notch worse than nord coil system. Very close. They blow nord away in vapor production though.
Afc is obviously here and though it's frustratingly on the coil behind the door, it is good. You can get a right tight mtl draw from closing it down to a pinhole width.
All in all definitely one of the top aio/pod devices out there. Has some annoyances though, it is not the perfect device yet. *note that I only use salt in such devices. I do not evaluate their use for ordinary ejuice performance and it is not a factor for me.