I used them during my Microsoft MCSE, Novel CNE and Cisco CCNP certification tests. Passing 20 exams in all. Of course I studied and knew the material. But there is the testing scenario and the real world. Rarely to these questions have anything to do with the real world.
What the strategies do is to give you a slight advantage to just guessing "C". I love how he talks about "smoke" to hide the right answer.
Just a few months ago, I purchased another copy before taking my next IT exam. Recently I passed my Cisco re-certification by 1 point after 6 months of studying. I know that the strategies made the difference between pass or fail.