Using a water jet is tidier as is it doesnt mark the material like a laser, but generally a water jet is slower at cutting and therefore slightly more expensive. At the end of the day its up to you
While we are on the topic of this thread and i have started dribbling on about water jets.
If anyone is going to profile out high tensile pieces for their car (ie suspension parts), your best bet is getting it cut with an abrasive water jet. Most HT steel plate is roller quenched and is HT due to its heat treatment, which makes them very temperamental to high heat, as this makes them essentially mild steel again. The other problem you have with introducing high amounts of heat into the metal is that it increases its hardness making it alot harder to machine.
Because an abrasive water jet is alot colder than the likes of cutting the part out by plasma etc, it will give you a much more user friendly and engineering sounds result.
And FYI if you end up using an abrasive water jet to cut out a part that requires machining afterwards, enquire about the companies tooling jet as it is quite accurate and makes life a fark load easier at usually not extra cost. I use it to cut out bearing housings, and exact drill sizes for holes that need to be drilled and tapped