I don't want to be too big a party pooper in my own thread!, but am moved to post a response to this.
I like the overall book design - the way the rules are laid out two-column style under generally informative headings, the way the Knights and Myths are set out in their two-page spreads, etc. I think there is a bit of information that is spread out and could be together - some stuff about holdings, for instance (some under Creating a Realm, some under People and the Realm, some under Domains); some stuff about NPCs (similarly), some stuff about exploration (most under that heading, but some in the Creating a Realm and Sites stuff). But that's the consequence, I guess, of the resolute commitment to the effective layout.
I'm not super-moved by the art. It does it's job, and combines the mediaeval with the more modern grotesque pretty well. (I say without being any sort of critic or qualified describer of art!) But it has no effect on my interest in the game.
What is compelling for me is: (1) the ideas expressed by the Myths, and the way these are bundled into Omens - it's clever stuff, personally in my view at least on a par with and maybe cleverer than the Fronts/Threats material in Apocalypse World, and maybe up there with In A Wicked Age. (I can't make a conclusive judgement about that because I've played IAWA and so know how well the Oracles work to instigate play; I don't yet have actual play experience of Mythic Bastionland.)
And (2), the way game promises to bring those elements into play - the combination of travel (which fits with knight errantry) and NPCs (in the Omens, the Seers, the locals with their folklore) and player interpretation (""When the group feels that a Myth has been resolved, reaching a conclusion of any type"), which reminds me of Signs of the Gods in Agon 2e.
So I agree that this is an aesthetically compelling and inspiring work, albeit for a different reason!