Aspect of chanting and its importance in percentages :
Just chanting the name of god is - 10% important
Chanting combined with one’s breath is - 30% important
Experiencing the fruits of our chanting is - 70% important
Experiencing just one’s presence and of oneself being separate from God is - 90% important
Experiencing of being one with God is - 100% important.
Source : http://www.articlesbase.com/spirituality-articles/chanting-the-name-of-god-with-ones-breath-857477.html