Does the mantra 'Nam myoho renge kyo' have exceptional qualities?

[astrokeen]

Has anyone experienced its practical or spiritual benefits? The organisation SGI professes it is a highly effective mantra in many ways and there are many people who will tell you how they chanted for and achieved many practical benefits. I was wondering, however, if people who are intuitive or on the path of enlightenment had sensed anything special about Nam myoho renge kyo.