I have tried many of this type of brain wave technology and have started to make them myself.
So far the best ones I have found are:
Brain Sync
SCWL Subliminals
Hemi-Sync
I have heard bad things about the I-doser guys - rumors that they do not actually integrate any brain wave technology into their sound files.... but this is highly speculative and just rumors... could be from someone who thinks it is a scam. I for one do not believe it is a scam; after doing the extensive research to produce my own subliminals. One thing I do find is you do need an open mind and must believe in it, quite like hypnotism, people can be hypnotized but not everyone can be hypnotized especially ones that do not believe in hypnotism.
You can give yourself suggestions as you listen to this stuff, I find that is the most effective.
The SCWL - Procrastination really worked on me, I was getting urges to make sure my house and office were always clean.
These doses or brainwave technology must be listened to for at least 30 days in a row for maximum effectiveness, otherwise it will not substantial effects.
Believe what you want I guess.
I have been creating brain wave audio and I then mix and integrate it into some of my favorite music and I find it works really great since my mind is in a positive emotional state when I am listening to my favorite song, combine that with subliminal suggestions with various brain wave frequencies and it has produced some incredible results.