They are different technologies, and affect the way the fuel is delivered to the injectors.
CR is superior in terms of allowing the ECU finer control of fuel timing the injectors are able to be individually controlled for duration and timing so each injector has phased control.
The PD engines create fuel pressure using camshaft driven pumps - one per cylinder it's clunky but has worked very well.
CR engines use a common high pressure pump - this is not timed or pulsed at all. The injectors are controlled electrically by the ECU.