I second Heathcliff77, I dont think it saves 2 weeks, They ask you to pay and you pay online. maybe a day or 2 are saved, but than you actually know that you have reached to that stage, or else you st away get copr and keep waiting.
I'd pay the RPRF with the e-APR application fee, reason being the following thread: http://www.canadavisa.com/canada-immigration-discussion-board/rprf-paid-month-ago-but-ppr-still-pending-connect-here-rprf-in-april-and-may-t428048.0.html