The thesis of 'Inventing the Victorians' is that they were a much more lively bunch than we would imagine. They were attracted to spectacle, sex, and advertising and do not deserve their reputation as staid and repressed. The book argues this theme in an entertaining way and is full of well researched examples. One criticism is that it might rely too much on anecdotal evidence, but scientific evidence on cultural issues is elusive.
The book is a great read for anyone interested in nineteenth century culture, and would probably prove frustrating to anyone looking for a text book or treating this as the key source book for an essay. In an academic context it would provide an alternative view and a few good examples. I would also suggest that the points the book makes are best understood against a background of knowledge of what was going on in England at that time.
None of the above should be read as criticism, but is rather an explanation of the type of book it is. Compared to more traditional history books it is an easy and interesting read - closer to a novel or a newspaper report than something to be studied.
Overall I recommend this book highly to anyone with an interest in what it was like to live in Victorian times.