The Wall Street Journal has taken it upon themselves to find out which airlines are the best at actually giving your your rewards.
Most Available Seats (so you can actually USE the points):
American Airlines and United Airlines, followed by Continental and Northwest.
Fewest Available Seats (avoid these airlines):
US Airways offered its lowest priced seats on 2 of 24 iteraries, Delta on zero.
Least Valuable Points:
Delta and US Airways were not only hard to book rewards seats with, they also required more miles than other airlines.
The WSJ suggests, no matter which airline you use: “Always check for discounted business-class and first-class tickets, which sometimes can be better values and even lower-priced than unrestricted coach tickets.” You may also want to book a coach fare, then use your miles for an upgrade.—MEGHANN MARCO