Slow juicers apply pressure on the item to bring out the essence and the flavor. This helps to break down the fibers and make the result easier to drink. The additional work for this process is what makes the design so slow. It is necessary to drop the RPMs in order to grind things out well. If you really like juicing, then have both types in your home for different food.
Slow speed juicers rotate at a much low rate than the typical centrifugal juicer. For instance, this could be 40 rpm in contrast to the usual 300 rpm or higher. These two types have their own strengths and weaknesses so choose depending on what you wish to do. For example, those who would like to juice berries will be happy with slow juicers while those fond on carrot juice will do well with the regular juicers.