In many ways I get the feeling that Shatner wrote this book because he couldn't cope with the idea of a star trek universe without Kirk. Kirk is the out and out hero in this book and while most of our other favourite characters appear, this is a kirk story.
The book shares Shatner's bombastic sensibility and addresses many of the failings of the 'generations' film. The book is a no holes barred adventure and is has a unique charm. If you enjoy Shatner's sense of humour and grandiosity you will like this.
Not only are the actors different but the characters they play only barely resemble the Discovery's crew from the previous 3 stories. However, despite this I still enjoyed it and was so pleased to be able to hear it as it is unavailable to buy in cd/ tape format. If you enjoyed the other 3 this is well worth a listen.