Waterjet vs. Plasma
A plasma cutter has a larger heat effected zone than a laser. It also has a large kerf so that you can't nest the parts as close. A plasma cutter has to have a metallic surface to strike an arc. It often times leaves quite a bit of slag causing a lot of cleanup.
A waterjet on the other hand can cut more precise than a plasma cutter, having no heat effected zone and no cutting fumes. The waterjet leaves only a small burr very easily cleaned up and often times not needing to be. The waterjet can cut thicker material with greater accuracy.
WaterJet Vs. Plasma