This was a good purchase. These tracks bring upon a nice euphoria and body-load after a few minutes of listening. Everything is improved from previous doses - the quality of the production is outstanding! The tracks include - what seems like - the harmonic x effect, which is an upgraded version of binaural and isochronic tones. The balance between the tones and the music is excellent - top quality. There is no white noise, which made me fall in love with it even more. Although stereo pink noise is optimal for binaurals as the brain can focus on the tones easily - my brain had no problem with these because the tones are in the same key as the music the whole time - which is fantastic because I can listen to the music and still get the effects! The price was expensive for 128kbps mp3s, and I completely feel I-Doser should be offering these as high quality mp3s at 320kbps with today's technology. I was disappointed to find out my $13 purchase was a low-quality mp3 (from an audiophile's point-of-view). I did not hear any artifacts though, so the audio was optimized for mp3, which helped a bit and the only reason why i didn't give it 3 stars. Otherwise, the effects and simulating experiences are of excellent quality. I do also wish the album art was higher quality too. But still, a good purchase none-the-less. Cut the price in half and you have your 128kbps mp3s worth their cost.