The missing link in the equation is availability.

When LOW awards are available, esp for intl in J, the miles have a lot of value, up to 3c on average.

When only high awards exist and the economy is in the dump, the miles are less than 1c

When award availability is non existent, like with United and Starnet blocking, they are useless =0c; like holding bonds in Bear Stearns after March of last year.

Unfortunately I have a M miles on both of these carriers DL and UA and it is very hard to burn through them while getting value from it.