The ultimate biography on the Queen will probably not come until after her death. But if we combine the plethora of existing ones, a decent enough picture comes out of it.
This biography adds to that picture to a certain degree. It’s not perfect, but it is easy to read and does not go too deep into the political side of things. I also appreciated that certain areas where I have read much coverage before, childhood, Margaret’s romantic affairs, etc. was not covered too much in detail.
At the same time, the book goes into more details on the latter aspects of The Queen’s life up to the wedding of Prince William and Catherine Middleton.
If you follow the British royal family with any sort of regularity, I think this can easily be skipped as there are few new and interesting things revealed. If you don’t, then it can be a useful and interesting read.