Baggage allowance - difference between *A & OW
 

I found out the hard way that there is one big difference between *A and OW on excess baggage rules when flying on a partner airline:
On *A, if travelling on a partner airline (e.g. I (NH*G) travelling on SQ) my excess baggage privelege as NH*G will be accepted at other *A airlines.
On OW, it is different. I flew on CX as a JL (One World Sapphire at the time). I had 28kgs, and the friendly but strict checkin agent at CX insisted I pay 3 kgs excess charge.
She said that on OW, the ONLY 2 things recognized for a OW Sapphire on another airline are lounge priveleges and mileage accrual. She specifically said that the excess baggage rules are different between *A and OW.

Is this correct, or was CX wrong?

The official status benefits are:

oneworld

Star Alliance

She was correct. There are no alliance-wide baggage privileges on oneworld.

That is likely the biggest disadvantage of OW. On Star for RTWs it is 2 x 32 kg, on OW it is inconsistent, but most of the time 2 x 21 kg. Since I sometimes need to take a lot of stuff i am getting Star RTWs most of the time and lost EXP 2 years ago.... I miss CX but not much else.