Though its superficiality is unavoidable (how much can you say about DTD construction or METAFONT in a few pages?), The Art of Electronic Publishing also exhibits a certain laziness in its use of materials: a Microsoft press release, quoted verbatim, hardly makes a good explanation of ActiveX, let along a useful evaluation; and, while it was good to see a mention of the Electronic Frontier Foundation, I don't think the complete text of the 1990 press release announcing its creation was a sensible inclusion. Most distressingly, given its subject, The Art of Electronic Publishing displays obvious signs of sloppy editing and proofreading.
The Art of Electronic Publishing does offer a useful overview of the entire electronic publishing world, with its many components and its variety of standards and software systems. It also contains plenty of pointers to sources for more information. Though much of the material was familiar to me, much of it was not, and I picked up quite a few useful bits of information from it. It was also a lot of fun to read.