For me, I prefer the 4" screen but I can handle a slightly bigger screen. Touch ID is a must and I'm glad they kept it. But the loss of the headphone jack will be bad, so I'll stick with my current SE as long as it's supported.
The original SE is about 4 years old now, which is close to retirement age in Smartphone years. It should be noted that the SE uses the same class hardware as the 6s, which is at the very bottom of Apple's currently supported list.
