I'll be honest, I gave up after a few pages of this back & forth about the top (& bottom) margins, valid arguments being made for either.
What I wonder is why this option needs to be tied to a (particular) firmware version. Kobo has provided their readers with advanced, sometimes a bit obscure options like how many pages between fullscreen refreshes, or changing font weight & sharpness. Why can't they just simply add a couple of check boxes to the reading settings to enable/disable the top margin info and the bottom margin info, just like they already have for page numbers in the side margin?
Everybody could have their preference, end of discussion (well, at least about Kobo forcing it one way or another... which one is better can be argued until the cows come home
)
Personally, since it's not a physical book, and increased margins do not add girth & weight by needing additional pages, I don't find it to be that much of an issue. On a practical level, it adds an extra page turn every dozen pages or so (depending on font size), and over the course of hundreds and hundreds of pages of the books I tend to read, it doesn't even register as far as I'm concerned.
On the Aura specifically, with its bigger screen and sharper text (making smaller fonts more readable) I especially don't mind a little extra breathing space so much. On the Glo & Mini it might be more annoying.