The exposure, or height, of diamond protrusion influences the depth of cut of each crystal, and subsequently, the potential material removal rate. You will find that larger diamond crystals and greater diamond protrusion will result in a potentially faster material removal rate when there is enough horsepower available.
Specifying the proper mesh size is the job of the diamond tool manufacturer. Producing the right number of cutting points can help to maximize the life of the tool and minimize the machine power requirements.