I'm buying the iPhone X, but I do have an issue with FaceID that nobody has really mentioned -- ApplePay.
Now, with touchID, you can hold your phone to a POS reader and it will bring up ApplePay, you then do TouchID -- bang it's done. With IPhone X, the process is, double click side button, then use Face ID then hold phone to POS reader. AND, if you need to change from default card, you have to use FaceID AGAIN. So the process seems worse. Also, I liked being able to hold phone to reader FIRST, to see if it even brought up Apple PAy -- that way you knew the merchant/hardware took applePay (usually). Now, holding the phone to the reader won't tell you that. Why did Apple change this? I liked not having to do anything to bring up apple pay other than hold phone near reader.
So now you have to double-click, authenticate via faceID, and then perhaps find out they don't really accept apple pay at that merchant, despite having the hardware that looks like they do?????? To me, this is a step backward.
See Apple Pay section here (starting at the bottom of page 4):
https://images.apple.com/business/docs/FaceID_Security_Guide.pdf