A great deal of perspective on comic books from two seminal creators, Will Eisner (for whom the Eisner Awards were named; creator of The Spirit and A Contract with God) and Frank Miller (creator of The Dark Knight Returns, 300, Sin City). Eisner was there in the beginning, and came back around the same time Miller started working in the medium, and whereas both have sufficient experience that their work ultimately has little relevance to the majority of what the public will think about concerning comic books, their insight into the history and art of it is invaluable.
Eisner departed the beaten track almost immediately, while Miller spent considerable time working on fairly typical superhero material, which makes their contrasting approaches, and therefore contrasting perspectives, the driving force of the conversation that is the book. If you're looking to have a comprehensive view of comic books, you might be disappointed.
If you don't particularly know Eisner, and are one of the many fans who later turned on Miller, you may end up baffled. As far as the latter is concerned, Miller outlines exactly what he chose to do differently in his later work, and if you as a reader thought anything negatively of it before, then it's your loss. Unfortunately most readers, and this has nothing to do with comic books, are extremely illiterate, and don't understand the culture around them, which makes for shallow readers.
At one point Miller suggests that a caricature of George Will he included in one of his comics is something he thinks his readers should be able to catch in order to fully appreciate the moment. And he harps a great deal on how he wishes comics were less frozen in their most familiar printed form. He and Eisner discuss why comics tend to be scorned as a viable art, and yet both of them weasel out of the dominant form they tend to take, which is superhero comics, which neither is willing to take at face value, and in fact look down on. Miller's one of the few creators who made his name with superheroes and has more or less stuck with them, but his stories have become more and more bombastic (in All Star Batman and Robin, the Boy Wonder he manages to alienate readers merely by having the Dark Knight declare "I'm the godd**n Batman," the latest evolution of his less than totally reverent approach that began with The Dark Knight Strikes Again, which is to say nothing about Holy Terror, received as something like holy blasphemy).
All of which is to say, and both icons are perfectly willing to question each other and so it's perfectly valid for readers to question them in return (Eisner has an odd respect for Stan Lee, but then there always seems to be praise for enduring names whether earned or otherwise; conversely neither has much positive to say about Jack Kirby, which for me is a first), as much as this is a conversation that you're glad you get to overhear, it's also one that hopefully makes you think about comics as much as they do. There was a time when I allowed Scott McCloud to do that for me, but it's a little more interesting to let Eisner and Miller act as the guides.