I loved most of the Eberron art, but I also found the comic-book pages, well, distracting, to say the least. I don't dislike comic book art, it just didn't work for me in this context. (I also hate Mignola, so anything that looks like his style loses points for me, big-time.)
That being said, Eberron has some of the coolest art I've seen in a long time. The picture of the City of the Dead is incredibly evocative, with the picture of Sharn right behind. I love art that gives me a sense of the setting, and this one does that in spades.