I've had one for years made by Clones Audio (they no longer make it) and it's well made compared to what I've seen online. I've read that one is supposed to keep it above head level and away from your gear but now reading that it's best to position it within 4' of your system, I may give it another try as I couldn't tell if what I was hearing was what I was hearing.
As for a sleep aid, I've been having more bouts of insomnia lately and decided to dig the unit out and place it back up on my dresser and have had an easier time falling asleep (a deep one) with more vivid dreams. My insomnia is now an occasional problem.
All the best,
Nonoiose