plasma is great for general fabrication with 1/2" and down for practicality. Waterjet is EXCELLENT for odd medium to cut and has great cut definition and precision within .001" yet very expensive to maintain the proper stream as you are changing $200 mixing tubes and orifices often. Laser is a great alternative to WJ but is limited on medium.
With the fab I do I would buy cnc plasma and outsource my needs for water jet or laser to make either one of those cost effective you must run them round the clock or build custom parts at a high rate.