The collected hardback edition of this is now out, and I have just finished it.
No idea if I liked the book or not. The constant genre-flipping obscures the plot and characters to the point where you have to work quite hard to keep track of who people are or what they are doing. Still, there are many fantastic ideas, and of course the art is lovely.
What really comes through is how angry both Moore and O'Neil are about the comics industry. Hardly surprising they have both walked away.