For the past 2 years I have been flying CX for all international flights...last September I decided to take PR because I was meeting a friend flying on Cebu Pacific in SIN and PR has the best flight to match 5J's.
I have to say that PR's service has been declining...on an A320, the crew did't even bother with last names...just a simple sir or ma'am. I've seen full cabins on CX and the crew can still manage to memorize our last names. Most of the time they were in the galley and never even checked if the passengers need anything. The Purser(ISM) never showed her face the entire flight, and since she was at the front galley, there was a constant stream of crew coming in and out the entire flight. Honestly it felt like coach service on business class seats and flatware.
PR's Mabuhay Classic has restrictions compared to CX's D/I class...they had 2 morning flights to SIN that day, I was taking the 10am(A320) instead of the 7am (A340), I called a week ahead and asked if I could switched to the earlier flight since J-class was wide open, they said I could but I have to pay almost 100 dollars for rebooking and re-issuance.