Folks seem to like to debate whether there is a "difference" in award availability between airlines, and I've seen a few studies which suggest that there isn't much difference. But I don't think the conventional wisdom that "they're all the same" is right. Rather, I think there is a significant difference in availability (and hence value) among the airlines today. From my experience, AA and UA win hands down. And I say that without any particular bias toward anyone -- in fact, my loyalties probably rest with CO, where I'm a longtime platinum.

Thanks to the free flowing credit card promo offers, in the past year I've had miles "to burn" on almost all the major carriers. And because the miles are easier to obtain (what's another credit card application? ), I've been more willing to use them on trips I might otherwise have paid for. Like domestic trips to obscure U.S. airports. Ever want to fly to Jackson Hole? It can cost a fortune. But standard award tickets are generally plentiful on UA and AA (and not plentiful on, say, DL).

And mind you, "partner" airlines don't work. It's a bear, for example, to find free seats on UA using US miles. The "bucket" is completely different, and availability is far worse.

Mind you, my experience is mostly planning award travel in advance, like between 2 months and 6 months before departure. It's also mostly looking for coach awards. The "last minute" picture may be quite different, as might be FC travel. But if you can plan in advance, and will take coach, the difference is dramatic. For a trip to transcon trip to Fresno, for example, UA had about 8 possible connections available at standard reward levels. DL? Zero. On a trip to the Caribbean, AA had almost any flight I wanted. DL had zero availability for weeks.

As you probably can guess, I'd rank DL the worse for reward availability, and I'd put US and CO only slightly better (I don't have enough experience with NW's program -- they're availability through CO and DL tends to be pretty poor, however). But the main difference is between AA and UA and everyone else.

I'd love to see some "intelligent" research be done in this area. I'd be very surprised if a carefully done study differed from my anecdotal (but extensive) experience.

Accordingly, I tend to value my AA and UA miles more than those in the other programs. Indeed, I seek out AA and UA credit card offers to build my account balances there because I know those miles have actual VALUE. They're a "real currency," unlike DL's Skymiles, which I basically consider "funny money" (I had to plan 330 days in advance to burn my otherwise "unusable" DL miles to get an award ticket to Hawaii.

I would like to see AA and UA publicly acknowledged for their efforts to make reward seats available. Indeed, if it were practicable, it might be a good idea to require the airlines to report their ff availability, so they might be more inclined to compete in this area. Right now, in this era of high load factors, I think there is too much incentive to try to sell every last seat, and leave the frequent flyers high and dry for award availability.