I can only speak for chanting of the hare krsna mahamantra, its the only one ive chanted. the name has so much power. in my case i was chanting under the guidance of a self-realized spiritual master, and i know that had everything to do w my experience. what i can tell you is that when i have been chanting in a state of surrender, which reading Srimad Bhagavatam helped me to understand what actual surrender is, certain things were removed from my reality, as if by magic. Things like fear, anger, sexual desire, and mental worries had vanished completely. Even 2-4 rounds a day gave me a total perspective change but 16 always just took those unwanted elements out of me. Attractions i had for lesser things diminished and my attraction for anything Krsna Conscious began to dominate my perspective. Whenever i was not chanting for long periods of time, i would always go back to "normal", feeling afraid of so many things, worrying, becoming attracted to physical sex etc. For me it's always night and day, whether or not i'm chanting, and it never ceases to amaze me.