As a 1st gen (for apple), I think it's a pretty good implementation. It is certainly as quick as the original touch ID was. I imagine that in another iteration or 2, it'll be pretty much instantaneous. And likely as not, more secure than current. I have no idea whether (identical twins aside) it is more or less secure than fingerprints. I have a couple of issue with it. 1) if I'm a bit slow in bringing it up to my face, it times out and asks for the passcode. I then need to press cancel to get another go at faceId. 2) I occasionally like to access my phone on the desk, which I now can't do as my face is not within range of the camera. 3) Once unlocked, you still need to swipe up. Surely this should at least be optional to fully unlock the device. Given the demo animojis stuff is pretty good, once unlocked, one should be able to indicate a "swipe up" by a quick upward movement of the head. 4) Probably not specific to faceID, perhaps my usage pattern may be different to others, but it appears most time I want to unlock the phone, it is NOT to access the same app that I was using last time. I'd much rather see the app icons again, rather that the last app. In terms of the reason for implementation:- I'm guessing their first priority was edge-2-edge screen. They couldn't get touchID to work in that scenario. Someone suggested to do faceID, which would allow the screen they wanted AND also give them a headline feature. The hardware used to implement face ID will I guess be used for other applications other than security, so they see additional legs in using the hardware to provide other "features". It probably also makes it easier to make it dust/splash proof. edited, as a couple of sentences didn't make it out of my head as intended.