I'm not familiar with this book or the DVD set. I believe you substituted "instant" for "flash".. Not sure why you would hide the title or the author...Anyway, read Richard N. Rust's review of this on Amazon. He is of the opinion that this is not for people who want to play piano on the world's stage, but it would be good for learning to play at home for your own entertainment.https://www.amazon.com/Play-Piano-Flash-Full-Video/dp/B00009A8ZXBest,Josh
I think where this is selling students short is the presumption of a set timeline to "learn piano." Are jazz and popular styles learnable in a shorter amount of time then classical? I would argue that such is confusing musical style with a good music foundation on which you may build on any style you wish to play. Realize that people study jazz, popular music, and world music at the PhD / DMA levels. It would be a much more reasonable goal to say that you would be able to achieve playing music at a certain difficulty / level in a couple moths to a year's time. It may be beginner classical pieces, or maybe some standard pop chord progressions, or maybe being able to pick out chords by reading a lead sheet. Treat music as a life long activity that you can continually enjoy learning from. You don't have to go in the direction of a concert pianist to get pleasure out of music.