I usually fly *A (CO gold), but being HK based, I often find myself flying CX even when I don't want to. For a variety of reasons, I have determined to not fly CX anymore unless absolutely necessary.

I fly to the US and China mostly, so China Eastern/China Southern/Delta are my options. I already have a skymiles account with a few miles from when I had to travel on NWA before - is there any advantages to accruing to a CSA or CE account?

I researched the Chinese programs, but the rules are quite different from the "western" programs so it was difficult for me to see if there were any advantages.

I mostly care about ease of using miles for redemptions and upgrades for long hauls.

Any suggestions?