So, let me rant some.
I bought this book because it was relatively cheap on Amazon, and the reviews were good. Boy do I wish I had looked at Goodreads as well. Admittedly, I am probably not a good target for this type of private biography, never having read any official account of Mountbatten's life and thus not knowing too much about his accomplishments. But this book was pretty shite anyway.
First of all, it is really poorly written. It's basically a "he said, she said" type of narrative. In fact I am really surprised that the auther is a journalist/writer, one would expect that with such credentials the style should be at least okay.
Secondly, the book is unnecessarily chatty, with quotations that seem basically unedited and provided word for word, just as they were delivered to the author. There is also no analysis whatsoever, and if there is one, it's so simplistic and apologetic that it's almost embarrassing to read.
Thirdly, the author is obviously very fond of Mountbatten to the point that the book is more of a hagiography than a biography. Mountbatten's conceit and self-absorption is cited throughout the book, but the author always follows up with an excuse along the lines "but his family loved him just as he was", "but he was actually right to believe that he could do things better". He obviously found Mountbatten's vices adorable and goes out of his way to paint a favorable portrait, even at the cost of contradicting himself multiple times throughout the book, depending on which view suits his agenda better.
Towards the end the book gets worse and worse, with quotations left unmarked etc., and the account turning into "every last piece of information I got on Mountbatten", even if it's completely irrelevant to the story, like: Mountbatten admired Chaplin and asked him to visit his home, but Chaplin said no, but then he said yes. Boom, there goes the entire story of the allegedly great friendship. I shit you not, people. Go read it yourself, or better, buy a different biography.
Two stars because I did learn something.