"With CX, the pecking order for op-ups are as follows:
CX Invitation
CX Diamond
CX Gold
OW Emerald
OW Sapphire
CX Silver
OW Ruby"

Hmmm Guy Betsy - I don't know about this. I travel a lot with colleagues who are CX Gold and have always been op-upped ahead of them. In fact, I have seen many sad faces as they head to the back of the plane. I have never asked anyone at Cathay how it works, so I don't know, but my personal experience has always been that the OW Emeralds (I have a colleague who is a BA Gold I travel with a lot) get an op up ahead of the CX Golds.