There were a good number of small mistakes, (for example a 2511 router has 16 and not eight asynchronous interfaces) which were mildly annoying. One would hope that it would have been better edited technically. Still, it's better than the other choices out there, some of which I've been very disappointed in.
The text was organized well, and was surprisingly easy to study, especially considering the subject matter. As a Cisco book, it seemed to have a clearer idea of what the test would expect; I noticed no major oversights as I took the test.
Overall, very good, with some improvements possible.