I wanted to add a data point. I was able to book an award on CX using a Mileage Plan award from CMB to IAD on CX in November. The awards to/from Sri Lanka price out as awards to India/Middle East and not to Asia. Still 67,500 miles one way in business for a flight half way around the world is very reasonable, and since the CX IAD flight does not offer first, I was fine with business class. Oh, and here's the interesting them BA.com showed one seat left in business, and I was able to book that seat. This is totally opposite my experience trying to use my Mileage Plan miles for an award to Singapore for last August. Sometimes, BA showed 5 seats available and I couldn't book an award. One hint, be sure to be transferred to the international partner desk, as the regular agents can't book awards. The other thing is be patient, it took over 45 minutes from start to finish as the agent I was working with had never booked a Cathay award and had to put me on hold multiple times as she asked for assistance from a supervisor. One final note, thanks to the forum I knew to ask to have the phone booking fee waived upon request.