I am facing the same dilemma too. I have a OZ Diamond card which most miles are accrued on SQ flights. Reason why I chose OZ is the fact I can enjoy up to 4 years of *G privileges. Currently, my status is valid till Dec 2012. Besides the published privileges which I have been enjoying, I rarely obtain the "unpublished" benefits such as Op-Upgrades. Also, my recent waitlist flights on SQ hardly get cleared even till the eve of travel.

I am now wondering if I should focus on accumulating miles on CX so that I can retain the Silver status. I usually travel around the Asia-Pacific region and as such, CX will serve me well to a certain extent, just that I will probably have to change plane at HKG.

I like Star Alliance for its vast network but I will like to give CX a chance. This can be such a tough call.