Yeah, here's my thing. I have my phone in the cup holder, upside down so it can be plugged in. I use waze to get everywhere and the phone just sits there facing me to glance at when the car stops. The address is set before I go and the phone in general doesn't get touched.
Occasionally the screen turns off because the side button gets hit. Right now it is easy to fix without even looking at it - just move my finger from the centre console to the top of the phone. No more dangerous than pressing a radio button (except the radio buttons actually need to be looked at to know which pre-set is being pressed).
The no-look, no-touch unlock that works so well now would be impossible with the new phone - if the screen ever turns off for whatever reason, I'm stuck with no map.
IMO, combine this with the inability to unlock your phone discretely and easily while in meetings or paying attention to something else at the office, and the lack of touch ID is a complete deal breaker. It is also incredibly gimmicky and pretty cheesy in general.
I usually pay immediately for cool new technology, but see no reason at all to make this jump given the added inconveniences. And there is no real reason to upgrade to the 8 instead, so for the first generation in a very long time, I'm just going to take a pass.