I like how the FP acts on the 6P. It doesn't have to be pushed to unlock the phone. Agree though that having the FP on the back is not optimal IMHO.
Oh and the capacitive buttons on Samsung phones is still software. It can be switched rather easily. Samsung just won't allow it. But I wish they would. On your 6P you can flash CyanogenMod 13 which allows for a lot more customization and a true battery percentage meter.
Sorry, should've clarified...aren't the capacitive button icons part of the bezel? Guess those could be lit differently to change the icon. And yes, I like how you only have to touch the FP sensor on the 6P as well, just hate where it's located--so inconvenient to any usage not involving holding the phone in your hand.