Originally Posted by
Santander
Echo this sentiment. Unless you are consistently flying premium fares on SQ (and even then...) KF is pretty much a rubbish programme compared to LH M&M and UA MP. If you plan on flying UA on their Asia flights it is definitely an option to consider. I would also recommend against choosing CA even if you end up moving to SHA, Chinese FFPs are utter rubbish.
I agree that KF is fairly useless, though I have found one thing I like about it: When you fly SQ and have to call in about changing flights and such, being a KF member gets you through to an agent almost instantly - even with no status and irrespective of where you credit your miles -, whereas you get put on hold indefinitely if you're not.
So it might be worth keeping an account with them and dumping the occasional shorthaul or hotel stay there just to keep it alive.