I have read The Power of Now twice and listened to the tape once. Since I am more of a visual person, rather than auditory, I found that reading was more effective for me than listening, although I agree there is a special energy to his voice. Of course, the real benefit comes from putting into practice what he writes about.
My thoughts? This is a must read for the serious seeker. Eckhart has a wonderful way of explaining the powers one derives from truly being in the moment, by focussing one's attention on what happens in the body.
I have been practicing this method on myself and also clients, and find it most transformational.