Is there much call for this as i have just been taught how to use out machine?

I would think it advisable to test even new injectors before risking a big build on the off chance you have a slightly dodgy injector!..Second hand ones a must..by cleaning them you got6 virtually a new set!!!

The machine tests for:-

Leaking
Flow rate
Spray pattern at various RPM loads
Precise cleaning
etc etc

Just tested a set of 1600cc injectors You wanna see these babies flow...LOL...no sign of any droplets either so should be ok for idle