Hi there. I use differently-designed beats for studying, meditation and sleep. There's now lots of choices out there on what to buy. I would have to say that I think for sleep purposes they are so-so. When you listen to them and you're sleepy already, they seem to work fine to aid in falling asleep. But if I'm wound up and anxious over something, honestly the music just grates on my nerves! Also, if you listen to the same material of binaural beats night after night, the brain seems to adapt pretty quickly to hearing it and the beats just don't work as well after awhile. That darn brain with it's amazing ability to develop tolerance strikes again!
I've just worked overall to improve my sleep hygiene drastically in the last few months. Listening to binaural beats after switching off the lights works some nights, but it's no replacement for good get-to-sleep practices. (Not that you're doing anything wrong in regards to sleep hygiene...I'm just saying). I think they're a good aid overall, worth the small investment of a few CDs or downloads. If you have severe anxiety or insomnia issues, though, I don't know how well they'd work over the long haul.