Not a great intro to the topic, as the book meanders a bit, focusing at times on events that, while not devoid of interest, are only marginally relevant to the Gestapo itself. Organizational charts and a chronological approach would have been a great help.
That said, it's well-written, vivid and approachable. The author's musings in the final chapter are as insightful in 2014 as they were in 1962 or 1945.