First of all, it should be said that there is nothing new in this little book for anyone who has watched the Evolution of Jack from when he first appeared in season 1 of Doctor Who, through to the end of 'The Last of the Time Lords' in season 3. For those who have watched (and rewatched) all the Doctor Who episodes that he is in, nothing in this book will be a surprise.
So why bother buying it, then? For me, primarily because of the pictures. It's full of various glossy shots of Jack, from his season 1 appearances through to season 3. That, and it is purely and simply fun.
It's a nice little, inexpensive book giving all the facts about one of Doctor Who's most lovable rogues, with lots and lots of photos to satisfy any fan.