I chanted the Gayatri for a number of years then switched to the M. mantra. G. mantra is basically the Yang side of a coin; M. - the Yin side. The G. mantra has more immediate effects in terms of organization structures; and I found it to be quite valuable in a working environment with a multitude of complex, mind-boggling exchanges of information. In such a hectic environment, the finite mind alone is swamped with an excess of information and simply gives up in a struggle to keep pace with coming up with a required output with a minimum of errors, and confrontations. The effect of the mantra is to take an initial assemblage of seemingly unconnected bits of information, and remarkably at the end of the day, extract an essential conclusion or product. There's no way one's finite mind could accomplish such a task without getting overwhelmed. To use an analogy, take a batch of coins and throw them up into the air then watch them fall to the ground. Is there some recognizable order in all this? The placement of the coins in time and space is an analogue to a vast array of things/events in an environmental setup. The goal is to make some sense of the pattern of coins after they drop to the floor and extract a conclusion. Or, think of extracting gold from raw ore. Thus, the Gayatri is a type of Philosopher's Stone that extracts the essential ingredient or core of a multitude of experiences and re-orients the energy toward what's represented in the meaning of the mantra. The M. mantra is far more YIN, with an emphasis on staying away from, or eliminating things that we DON'T WANT; rather than getting things we WANT (as with the Gayatri). I now chant on the M. mantra because my working environment is so hectic that my main goal now is just coming to work, raving a relatively nice time, and avoiding confrontations at all cost. The M. mantra is also called the "Cucumber mantra" since the words imply a separation out of the fruits of work from all of the baloney we want to be rid of. Ultimately, the Gayatri mantra (Yang); and the Mahamritunjaya mantra (Yin); converge upon one "thing" (so I have been told): Blazing, radiant Light and Celestial Sound focused at the 3-rd eye along with "TAT" (Truth - the Absolute). Nice combination!...and don't forget DHARMA. Both are Dharmic mantras. Last but not least, both are bad karma mitigating or eradicating mantras. But don't expect miracles right away. Benefits improve over the years.