The plasma is limited in what materials it can cut. For best results, it should be used primarily for steel, stainless steel, and aluminum. Non-conductive materials do not tend to cut well on the plasma. Thickness is also a factor in plasma’s cutting capabilities.
The waterjet is known for cutting nearly any material type. From hardened steels to softer materials like wood, plastic, and even food items like bread or cake, the waterjet will have great success across the board. Because the waterjet does not introduce heat into the material being cut, it is not limited by thickness and can cut thicknesses over 12” steel (though this would take a long time to cut).