I use GTD to clear my mind of noise.
By capturing everything in my world that does not warrant action in the present moment, my mind is more relaxed, and I am freer (is that a word?) to focus on what is happening in front of me, now.
Am I there yet, 100%? Not even close. But my feet are pointing in the right direction, as opposed to where I was before GTD. And it's the practice that counts.