I own a copy.
It's really interesting and Morrison is a superb writer. Most of what I've read so far is about closely examining change within comic books against change in the social context at that time, which is all stuff I've read about before but never with the depth or wit with which Morrison parses through comic history.
That being said, I can only read so much at a time before feeling like I'm disengaging from the writing and then I have to stop because I feel like I'll just entirely miss the point of whatever paragraph I'm on.
It's really a series of essays, I guess, and that can feel pretty heavy after a little while.