Also keep in mind, that when you do a same day confirmation, you lose any confirmed upgrades. Delta is essentially reticketing you for free, and eventhough your second segment is the same, they have to rebook the entire way for the class you paid for, not just the one segment your changing. I learned this very recently. Obviously, you will be put on the standby upgrade lists, and if there is still inventory in the V and X buckets, they can put you back up front. But with all medallion levels already having the opportunity to clear, chances are slimmer and you might want to expect batteling it out at the gate.