I needed about 100 questions in a hurry and didn't have time to do all the research for myself. This book helped. It was OK as a source of inspiration for most of the questions I eventually wrote but as a definitive quiz book, well, no, it's not that.
In 3 sections, the easy are just too easy - OK as I say for a prompt but not much else. The medium questions were OK and some were quite challenging. The difficult questions are often just that - too damned difficult!
But I can't complain over all - it gave me a direction with 100 questions and that's all that was needed. Just don't expect to be able to use it directly as a source for your next pub quiz. You'll get into a lot of arguments!