Originally Posted by
avidflyer
The only thing I would add is that if you plan to hit MM status with UA it is miles and miles better than the bone they throw you at DL. UA MM'ers get lifetime Premiere Exec (Premiere Exec is the equivalent of Gold on DL) and your spouse also gets lifetime Prem. Exec. "Annual" FO for Delta MM'ers (I am one) is embarrassing.
The problem of course is that with UA, only flight miles on UA and COPA count toward MM qualification status (no class-of-service bonus EQMs no *A partner EQMs, etc.), whereas DL counts all MQMs (including fare bonus MQMs and partner MQMs)