I'm thinking that US might give the best value in terms of bang per mile. I just redeemed 80K miles for a business class award from the East Coast to Europe using Lufthansa for the longhauls, and US and UA for the domestic hops. This was for travel within 5 days of the reservation earlier this week. I checked a similar trip on Delta (not *A, I know) but it was in the 150K-180K mile range. Similarly, it was 180K miles for an award on UA.