I was interested in reading answers to the OP's question, and I'm surprised there have been so few. I know the authors advocate running barefoot or in minimal shoes. Perhaps they're not members of BRS, but I'd be surprised if a few more of their readers weren't. Their Facebook group has over 1000 members, and I'd expect a bit of overlap between that group and this one.
Also puzzled by BarefootBC's comment, since focusing on 180 cadence is discussed on the website as one of 7 'myths':
'... In summary, 180 steps per minute is an arbitrary figure. Cadence should come naturally and not be forced. Even if setting your cadence to a specific count was a worthwhile goal, it would be nearly impossible to know how to calibrate it for each given speed or your current level of fitness and technique. Getting fixated on cadence doesn’t make you a better runner, it just helps you count 180+ bad steps.
Learn to land balanced and all aspects of your running form will adjust naturally around this, including your cadence. The key to reducing an over-stride and increasing speed is a balanced landing. This will enable a springy take-off, giving you more airtime, a longer stride and also a higher cadence.'
I haven't read the book myself, but maybe BarefootBC, flamee or anyone else who's read it could tell us more about why they have or haven't found it useful?