He provides interesting details on matters often not discussed by classicists. As a librarian, he is very much aware of the importance of furnishings and catalogues in the use of any library. Unfortunately, when he discusses these matters, he gives no references for his statements, be they from modern publications or ancient sources. When he refers to different theories and interpretations, he never names the scholars who make them. Instead each chapter ends with a short description of some works not directly mentioned in his discussion, followed by a very brief listing of some more.
All references are to works written in English only.
Nor is H. always up to date. Both groups, librarians and scholars, should be more aware of each other's work. Because H. uses modern terms throughout, he leaves the impression that libraries then were very much like those today. I give three examples. I don't think any classicist would use these terms.