For flyers who travel on all but the deepest discounted economy tickets, Delta's Platinum Medallion upgrade policy is more generous than Northwest/Continental.
Furthermore, I believe Northwest's coach product is more deserving of the "squalor" label than Delta's coach cabin.
<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by bonzaiflyer:
We're quite happy with your choice and wish you well sitting in coach squalor on DL while we enjoy NW's (and CO's) more liberal domestic upgrade policy.</font>