They are not kidding when they say you need a sifu and this is only a suplemental tool. For $50 I expected a ton more than what was offered. You are better off putting your money into extra class time with a certified instructor. I would not recomend this item unless your sifu has specificly told you to get it.
I found the CD an excellent overview of the northern praying mantis style. There is a wide range of technique, and the applications span the gamut of readily apparent to surprising.
I must disagree with Mr.Ortiz' evaluation of the CD, as I have seen his work as well and can compare the two. The fact that he may not be familiar with some of the applications in the CD does not make them incorrect, merely unknown to him.
While not having a sifu at your arm is a disadvantage, the methodical teaching style in the CD and the multiple angle format make it as close to the real thing as can be obtained.