4 jets doesn't seem to improve the speed of the rinse it just reduces the pressure same with 3mm jets, i dont know if it produces more litres per minute, it must do but theres no pressure and i like a jet wash. I've tried it all 6mm, 8mm, pencils, fans, 4 jets, rinse bars etc.....
Best flow to be had is 2 pencils with 8mm hose and no controller so you get a nice bit of pressure build up.