I picked up the book because I was curious to see how closely the Michael Mann/Johnny Depp flick adhered to the public account.

Short answer to that question: not very closely, which in some ways is just as well, since the movie (not one of Mann's or Depp's better entries) is vastly more entertaining than this book. Burrough assembles a heap of resource material to piece together a very thorough account of who fired how many bullets to injure/kill whom, in order to obtain X-amount of dollars in a bag. Burrough portrays the gangsters of the 20s and 30s as worthless thugs, and the fledgling FBI as bunglers of the worst order -- an account which is true enough, on one level, and long overdue. There is, however, little sense of the spark that captured the public imagination. It is a long and arduous account, and often reads like it was assembled by committee. The speed-reading quotient for this book is very high: 90%+.