The benefits of juicing have been discussed tens of thousands of times. I believe in juicing if you juice right. That means no fast spinning juicers, centrifugal types. Only the slow compressed types, or those that work with gears, moving very slowly. The end result, pure-energy, power and vitamins in their best state. No heat, cool, and sweet.
In case you want a very good juicer – buy Greenstar: http://www.greenstar.com