Originally Posted by
iwpingmu
Thanks for the input, do you also think (normally) delta mile may worth less than $1 per 100 miles?
I only fly AA and UA, if any AA or UA voucher $250 can be exchanged for 25K, no doubt that I will do the exchange.
It seems delta mile has at least 1/3 less value than AA or UA
I think the general consensus is that DL miles are worth less than UA or AA. Not always as those good deals can be had but they are much more likely for Medallions and those who have greater flexibility. For the flexibility alone I think the $250 voucher is better (and of course the earning of MQMs

)
But as
elmococker said, if the voucher will not be used by the expiration exchanging for the miles (which don't expire) is the better option.