I just got the Art of Marvel movies compilation that contains both Iron Man movies, Thor and Cap A. I got the paperback version of it, and it's terrible quality. The printing quality is fine, but the paper weight is horrendous. It is so thin and flimsy, it collapses under its own weight. You can't hold the books up to read without them flopping and curling over. I'm afraid to handle them lest I tear the tissue thin pages! I've had plenty of paperback how to books that are about the same size (IJ and the Crystal Skull Photographic Journal, the Making of the IJ movies are the most recent ones I got) and bigger, and they are much more sturdy. You literally have to set them flat on a surface in order to read them. And even then I'm afraid the binding will give way.
My advice is spring for the hardcover editions.
I got the paperbacks because the price had gone down to about $60. And I had $20 left over from a GC, so I only paid $40 for it. I'll live with it. But I definitely would go for the hardcover versions if I had known.
Otherwise the content is good. I wasn't crazy about the design--much too busy and almost amateurish. The Making of the Dark Knight Trilogy book (hardcover!) is much better designed.