I am a 1K (100,000 miles) on United who already has accumulated 100K miles for the year. Since I'm a bit concerned about United's long-term health, I am thinking of hedging my bets by building up miles in another FF program during the rest of 2004. I travel mainly to Asia and the East Coast from San Francisco, and occasionally to Europe. I'm interested in carriers that would get me free flights or upgrades to these destinations. (I normally fly C class to Asia and fly economy, but upgrade, to the East Coast and Europe.)

Within the One World alliance, any thoughts on whether Cathay, BA, AA, or another airline offer the best options, in terms of their routes or programs (including mileage exchanges with other One World airlines)? I'm calling the FF programs of these airlines, but also would appreciate any insights on whether, as a practical matter, a mile on any OW airline is worth a mile for a free flight on another. (I assume that miles from one can't be used to upgrade on another.) Any other info I wouldn't necessarily get from the FF programs also would be welcome.

Thanks for any advice and other feedback.