well i'm still not that enthusiastic.
My main night out is dancing, and when using the happy i find that the first 2 hours after usage my dancing is quite bad, just don't feel a match between body state & brain state. After 2 hours my dance improves but i also more or less lose the mental state. I also find this when using espresso and after that playing a high energy game like table soccer, i just play baaaad .. so for me it does not feel like you can instantly change your whole (body & brain) state by just influencing your brainwaves.
The sleep works but, like i wrote earlier, i have another one with which is tend to feel more rested the next day .. this is probably related to a difference in frequency? Ultra deep does feel deeper then my other sleeper .. but maybe deeper sleep does not automatically lead to more rest?
Also my tinnitus increases after using esp the ultra sleep, this seems related to the audio-technology, am still on the mp3 version though as my cd's have not arrived yet.