I upgraded from 1st generation SE. A real good jump! And it shows. Fantastic screen. Located like a larger iPhone 4/5 / 5s in the hand and is vessels fast. Installing apps is probably five times faster than on the SE. However, I still have a hard time getting used to the fact that the ENTIRE front is a screen. You do not really know how to hold the phone when the screen is on. And you learn to learn more gestures than those you have managed from until now.
I prefer touchID before faceID but you have to learn to live with it.