I just think the buttons should be a user choice. If you do not want static stuff taking up space on the display, configure so they pop up as needed or provide the function in another way.... like on the iPhone and iPad. IMO, it is not "really" a 4.7" display if you can not use content on it durectly for apps. Ditto for tablets.
This reason alone trumps the One and makes the S4 supreme overlord. Presuming we get a 32GB version, which BTW even more media folks are picking up on this- and consumers. Significant in that the device just launched and still in not too many hands yet.
Added: I thought I read where KLP was going to provide options for the nav bar, but I may have read into it what I wanted to.