I normally do not travel with excess baggages... I fly over 150k on an annual basis with various airlines. It's just that I was on a 10 day golf trip to Scotland. With the equipment and all, it went over the BA limit of 20 kg. Since I booked the entire trip through CX and that BA is part of the OneWorld alliance, I assumed, at the very least, they would recognize one's status with their partners.
After this experience, I am seriously considering moving to Star next year... after having reached Diamond with CX this year.