I first read these essays in college when I was studying theatre. At first I was alarmed at how severe Mr. Simon could be, that may have been what kept me reading. He can be ruthless when discussing a work he dislikes. He isn't afraid to say what he thinks even if what he has to say is likely to be unpopular. Mr. Simon, however, is perceptive and well-educated and his observations generally based on experience and knowledge.
Many people have failed to note that he can be just as intensely focused when discussing something that he loves as something that he despises. The joy that he takes when he sees a first rate performance, design, a well directed play is infectious.
John Simon is the inverse of many modern critics. He uses his extensive knowledge of the arts and sciences to render opinions and judgments that are clear and precise. Many modern critics seem so enthralled by a single theory or school of thought that they will ignore incompentence if the work presented fits into their perspective. Others write so obscurely that one can't tell what they think of the work they are considering.
One always knows where John Simon stands so that one can disagree or agree with him.
Simon's greatest limitation in my opinion is a pervasive shallowness
Though I had not read or seen performed nearly all of the plays John Simon discusses in this book, the author's mastery of the language of dramatic criticism was a pleasure. While I can respect that, however, I kept thinking that this is an individual I would not enjoy knowing personally. I don't know how this book got into my personal library, but I previously last read it in 1980. It was more meaningful this time with the help of Wikipedia for background information — I wish I'd had time to keep reading notes on the extensive vocabulary he used.