This all comes doen to the GA being the final authority when it comes to getting the plane out. Last night on Flight 355 MSP-SFO I did not get upgraded flying on a M fare. I know I was #19 on the upgrade list when I checked in at DCA. There were numerous problems last night with weather and they subsituted one 757 for another. The one we got had 24 first class seats instead on 22. Of course, as you probably figured the plane went out with 2 empty first class seats. How do I know, I was sitting in 16C. I actually saw someone ask the lead flight attendendant to move up to one of the seats, which he did. I didn't bother because the seat next to me was empty and I was already was content where I was sitting.