I enjoyed "Who's Afraid of Opera?" very much, and have recommended it to several people.
I'm an opera "newbie" who is interested in opera but didn't know where to start. I had not been tempted to read other books about opera that for the most part seemed dry and impenetrable. Michael Walsh's book, on the other hand, was more like having an extended and animated conversation about opera over dinner or while walking along with a friend. In fact, until I had finished the book, I treated it as such, taking it with me everywhere, like a companion, and was eager to read it when I had a spare moment.
Michael Walsh is indeed opinionated, but that is part of why I was so stimulated by this book. It made me want to go out and see/listen to the same operas he discusses--to determine if I agreed with his opinions! Whether I agreed with him or not, I was consistently entertained by this book and would recommend it to anyone as a good "starter" book to the world of opera! In "Who's Afraid of Opera" Michael Walsh will both irritate and delight you, as anyone worth talking to should.