Not sure if the glowing critic comments were by anyone who has actually read the whole book. If you merely read 4 or 5 pages you would get an excellent impression. Unfortunately, reading the whole book in one go is a dyspeptic experience.
On the plus side you will not find so many references and quotes on these two in any other book. A wonderful source of reference but reads like a dictionary!
A well researched comparison of two musical giants . You may not agree with all the authors views but his reasoning is clearly defined and elegantly presented . This is a must read for all opera lovers