I just finished reading Tolkien: Man and Myth by Joseph Pearce and while interesting, it is not a biography. The book is really a commentary /interpretation of Tolkien's works based on Tolkien's spiritual beliefs. Pearce also includes a great deal of "criticizing the critics" due to the controversial results of the Waterstone Poll. I agree with much of what he has to say about those who criticized Tolkien's works. I did find, however, that he took Carpenter's comments out of context, rarely quoting more than a part of a statement.
What biographical information is included in the book is taken from Humphrey Carpenter's books, which he acknowledges.
I do have a couple of more Tolkien biographies on order so I will let you know what I find out. In the meantime, I still believe that Carpenter's book is a very good biography about Tolkien, his family, friends and the events in his life.