Hemi-sync, holosync or lifeflow

Your remark is quite correct. It is true, that the goal of Gateway series is something more than entrainment only. However, they use tools which seems to be very effective in the sense that one is trained to get into Focus 10 and others very quickly. I don't know to which brain frequency F 10 or F12 or F15 correspond, but these foci should be somewhere in alpha or theta range. The advantage I see here is the possibility to learn how to get into 'deep mind states' almost instantly and without help of any entrainment CD.

So my question is if somebody can confirm this opinion due to his/her own experience.

I totally agree. What are you trying to achieve??? Out of body experiences?? Go with the Gateway program. Want to go down to alpha or theta?? If you want to get down to alpha to do some Silva Mind Control style programming, then holosync would do the job. I am not familiar with lifeflow so I can't comment on that. However, I have been using brain entrainment cd for over 20 years and from my experience it takes multiple listening/doing to go to level (alpha) or deeper at will. Again, it all depends on your goals. After you have condition your self over a period of days, then you can faithfully stay awake at the different levels. How I learn to stay aware at what is called the alpha level is to go to this level 3 times a day, for 20 minutes per session. I also practice going to level when I was wanting in line, in the grocery store, stuck in traffic (eyes open of course), and even when using the bathroom. I wanted to be able to go to level at will. I did this for 100 days straight. Then I wanted to go to theta, which is 3-7 cps. Since I have yet to buy an eeg to objectively calibrate that my brainwaves are indeed in theta, I use the complete loss of awareness of my body, as one distinction. I tend to enter a dream like stage. If I lose control, I often find myself in a lucid dream. While entertaining, my purpose is not to dream, thereby produce hallucinations, but to remain aware and "go" after my particular goal. This is very difficult to do but it can be done. Ken Wilber can enter theta with his eyes open!!!
Again make your buying decision based on what your goals are.

I purchased some brain sync cd's a few weeks ago. It seems like this is a reputable company and its founder, Kelly Howell, has a pretty good biography. I listened to these 2 CDs for 2 weeks, alternating every other night. They were great, but now after 2 weeks I am experiencing extreme "upheaval" as the Holosync company would describe it. I think that this has to do with these 2 CD's being deep theta wave soundtracks. Anyway, I'm semi-freaking out. The symptoms appear to be alleviating somewhat, but nonetheless I'm done with this technology. All change must come from ourselves; nothing from the outside is ever permanenet, be it drugs, other people's opinions, or binaural beat technology. Has anyone else had similar experiences?