I used this book for one of my courses in professional computing.
I find this book to be quite readable, the essential and pertinent concepts are well-explained, and the scope of coverage is comprehensive. All the necessary aspects of HCI, the models of the user, interaction, system, are touched on. The chapter regarding the usability paradigms and principles is elucidated in a structured and systematic way, and the chapter on the dialog notations and design introduces some commonly used notations, including Petri Nets, which are also in common use in other IT topics.
This book does not delve into the more esoteric applications and theories behind HCI, but I would not necessary classify that as a shortcoming, for the book was probably never meant to be targetted at advanced researchers anyway.
All in all, I would highly recommend this book to those who want to get into the fundamentals of HCI, be able to use the concepts for practical applications in daily life, and who need a handy reference.