hi all...looking for some opinions...my husband is currently EXP on AA and Premier Exec on United....in the next year he will be making 4 or five round trips to Belfast....looks like it will be on CO....he has no miles at all on CO but about 25000 on DL....should he get the credit for flying on CO or DL... is one program better than the other....will he get the same number of miles on DL as CO for flying CO??? Thanks for your thoughts

Theresa