(9) In terms of ease of use and the potential to provide satisfactory performance, PID controllers have a cost/benefit ratio that is difficult to compete with other types of controllers.
(9) In terms of ease of use and the potential to provide satisfactory performance, PID controller has the cost / benefit ratio that other types of controllers are difficult to compete.
(9) In terms of ease of use and the potential of providing satisfactory performance, PID controller has a cost/benefit ratio which is difficult for other types of controllers to compete with.