While I fully appreciate Delta's efforts to improve the inflight experience, I'm nevertheless bothered by the fact that my Medallion upgrades, for the past 40 flights, have only cleared at the gate. Even on Continental, I get upgraded within my 5-day Plat window significantly more often. Last Wednesday, my flight from ATL to MIA showed 14 available F seats (exactly how it was at the time I booked the flight) and Y was not full, yet Delta did not release any "V" seat. Perhaps Delta should be honest about Medallion upgrades, i.e., there is no point in assigning a 3-day Gold Medallion window (in my case) if the upgrades will never come through around such time, regardless of how light the F load is. After 40 segments, I'm beginning to see Delta's systematic lack of "V" inventory. Also, DL is the sole US airline that only permits domestic mileage upgrades on Y,B, and M fares... as if Delta's First Class was worth it!