The smaller screen must really be important for you to give up 2 hardware features and not be able to run iOS 12 as well as the iPhone 7 which is also going to be released this year. If that's the case whatever floats your boat.
I must be the crazy one, but I thought the move to 4" screen was silly. Now they have the "iPad nano" (sorry, iPhone 6+/6s+), and I can't believe people really like something that big!
Truth be told, I still feel the 3.5" was the best size and would pay flagship price to get a current gen 3.5" iPhone. Instead I have to settle for the 4" SE...