I've been going back and forth between the two but I genuinely can't find a good reason to go for the 8 over the 7. Wireless charging is incredibly slow with benefits and tradeoffs concerning its convenience. A11 while impressive, won't make a difference to what I use in terms of apps, browsing, texting etc. Battery degradation these days has a far more substantial impact than older SoCs. BT 5 won't make a difference to my AirPods, as far as I know.
The camera, which is important to me, so far seems to reproduce very similar images to the 7 with slightly more saturation, which is something I've tweaked post anyway with previous devices. 60 fps is impressive, but I prefer the look of 30 which the 7 can deliver in 4K.
If Apple hadn't removed 128 gb and generally made the 8 so exorbitantly expensive here, I might have bought it. But their added arbitrary markup have finally caught up to them.