Craig,
I have practiced meditation many times. I came to it when I was going through my protracted divorce and I found it helpful in stimulating a sense of peace and relaxation.
I never used a mantra but only focused on my breath as it went in and out.
My experiences were frustration at first. Not easy to quiet a racing mind when you've been living in a frantic state for a long time. But over time I got better and more relaxed. Then I noticed that the core things that were negatively affecting me would come to mind during a meditation session. I found this enlightening because I had been living at such a fast pace that I was completely unaware of these things.
If you want to try meditation in its most basic form, I recommend getting a guided cd or tape to get you started. My first one was "The Art of Meditation" and it's perfect for the beginner/newby.