So...I got mine a few days ago. I've been using it nearly non-stop, several times a day. The effect is subtle, but it's there. Sometimes I have to listen at high intensity for all 45 minutes and only start feeling it at around the half-hour mark. I'm also pretty sensitive.
My wiring is pretty screwed up by early childhood trauma and I'm anxious all the time with peaks around material security. Benzodiazepines are supposedly contraindicated for my diagnosis (this isn't really true, but the local mental health zoo is 'treat by number'), so I've been taking an herbal product called SECURUS. It's got kava, GABA, passionflower, and bacopa. I've had help with extreme anxiety using a very powerful water-process kava extract from hawaii but although it kicks in quick and is very obviously effective, it doesn't last long. It's best for severe anxiety or panic attacks. It's also very expensive.
So...SECURUS has taken the peaks off my anxiety, which is great. I didn't even realize how anxious I was until I'd started taking it for a few days. However, there's still a sort of 'baseline' anxiety that, although more manageable, is still there.
About the Nervana:
1. The earbuds are not high-quality sound. Bass is really not there.
2. Not everyone is going to feel comfortable with the feeling of little shocks in your left ear for minutes at a time.
3. Yeah, it definitely works. I'm near the end of a 45 minute session now and I'm sort of giggly.
4. I've been sleeping like a corpse since I started using a session before I go to bed. It won't put me to sleep if I use it off my 'natural' clock, which is now tuned for sleeping during the day, but when I finally DO sleep, I sleep deeply for eight hours.
5. Earbud fit is required. I've difinitely gotten both better effects and better sound since using the largest buds that come with it.
6. About those buds, they use a very specific kind of earbud, especially for the left ear. There's a blue dot on the left ones and if you don't use that earbud, the product won't work. It's semi-conductive.
7. About the sound quality - once the effect really kicks in, your music will start to 'sound better' due to the way you feel. I've rarely had music stuck in my head like I do after listening to it with Nervana. It certainly won't replace my good headphones, but it makes the poor sound quality a little more bearable.
8. You can run it on preset programs without music but I haven't done it yet.
9. Buy rechargable 9-volts and a charger. The original 9-volt that comes with it lasted about 4-5 days of heavy use.
10. Saline. If you mist the left earbud with saline, the stimulus is more powerful. They provide a refillable sprayer with the product but they don't provide saline because they don't want breakage of the saline container to ruin the unit. Contact lens saline works, but I'm an RN and I'm always accidentally taking sterile saline syringes home. Now I have something to do with them besides throwing them away.
My longterm hope for Nervana is that I can somehow semi-permanently tone my vagus nerve in such a way that my parasympathetic nervous system counteracts the screwy wiring I built up as a young person due to unstable...well, everything. Doing it with the herbal product and Nervana in the meantime is really proving helpful. I've been fighting my anxiety for so long that my horizons (personal, professional, artistic, etc) have all been stunted and the world has been mostly grey for quite a long time. The last few days have been better. Work isn't nearly as painful.
Overall, I'm happy with the product - but not for its sound qualities.