Agreed 100% on American. Statistically it is proven beyond any doubt that they have a higher percentage of seats available for frequent flyers. They also are far away the best in terms of cabin and lavatory maintenance.

By far, for purposes of upgrades or frequent flyer seat availability, the worst are Continental, US Airways and Delta. The only statistic you need for those three losers are:

1.) Attempt to book a standard mileage award in any class of service to any city on their route map, for any time between June 1 and September 15. You will find none available.

2.) Then, go to their sites and begin the process of booking a paid first class or coach ticket, and then check the available seat map. About 80% of the time you will find that their flights are only 30% sold.