I have practiced TM. I do not really practice anymore, though I probably should. I'd benefit from it. Just laziness I guess.
It pretty much has the benefits of any relaxation technique. What I liked most about it was the philosophy behind it. It is a very permissive technique of meditation ... vs. a more hardcore, zazen approach (where the mind is seen as an enemy) ... or at least the zazen approach I learned.
While I was doing it I think I was dropping deeper into some stuff I didn't want to handle at the time.
What do you want it to do for you? I'd recommend learning the approach if it isn't too expensive for you. I had a really good teacher.
The Relaxation Response teaches a very similar technique, and it costs less. Basically, just allow your mind to rest on the mantra and allow whatever thoughts and feelings you have to be. Also, if the mantra changes inside your mind, allow it to change.
Sometimes the mantra, for me, became a pulse that was more of feeling or pulse of thought than a sound. Often synchronized with my heartbeat. Hmmmm ... now you've got me wanting to start again. I think I will.
