If we all think the same and had the same beliefs then we could say our brains are wired the same. As it is we all use our brains differently so for some people Audios like Holosync will make a fantastic difference and others none what-so-ever.
To me the biggest mistake someone could make is to stop exploring, classifying all entrainment type CDs or tapes as useless. If holosync or something else, doesn't work for you let go of the guilt or disappointment and spend the time using something that does works for you. Perhaps later when you return to Holosync or whatever, you experience a better result because now you are ready for the experience.
If you want to grow, you need to take the risk try it and see, if it doesn't work for you return it or shelve it for a later date. If you don't try something, you will never know what your experience might have been if you had...
Alex