I really enjoy this feature because it gives users who read long posts (especially on mobile) quick access to the navigation bar when they need it, but without

I really enjoy this feature because it gives users who read long posts (especially on mobile) quick access to the navigation bar when they need it, but without the screen-hogging characteristic of older position:absolute nav-bars. With regards to the visual distraction, I find that I almost never scroll up unless I'm done reading. Continuously scrolling down feels natural, and in this case, the header will stay hidden regardless.