I felt so much shame when someone said they were going to upgrading to the 8... from an iPhone 5S.
Currently leaning on going for the X, if Face ID will be setting the stage for the next decade (absent of Touch ID), I think it's pretty safe to say get an X and not get an 8. Being so into the smaller form factor, I think the X being able to pack all the advantages of a plus into it, and including a bit more has more value. Photography also being a factor, I was sick of all the smaller non-Plus models prior to the 7 not having any optical image stabilization... will be looking forward to better photography in the next two months...
Though I will have to say if Touch ID comes back in-display as a successor to the iPhone X in combination with Face ID. I may be forced to sell the X and get that newer model just because I really wanted in display Touch ID this year and all leaks pointed to Apple wanted to get it in there, but failed... which I think is why the shipping timeline was so skewed. There probably wouldn't even be an iPhone 8 if they were able to successfully get Touch ID integrated with the OLED display in the X.