Mildly OT, but here are my experiences these past two weeks:

10 March (Wednesday): HPN-atl-FLL:
I used 4 credits to upgrade my scheduled evening flights, but tried to standby on the morning HPN-ATL flight. I was successful with the standby, and I got the upgrade (with one more seat open in Biz class), BUT I was told that standby passengers who have upgraded to Biz class on their original itinerary have a lower priority to get a Biz class seat on a standby flight than A+ Elite complimentary upgraders. I.E. they upgrade all A+ Elites with a reservation on the flight at T - 40 minutes and then at a few minutes before closing the door they take standby passengers; any standby with an upgrade will not get it if the Elites have already filled the Biz class cabin.

On the first ATL-FLL flight after my HPN-ATL flight arrived it appeared that there would not be room for any standby passengers (roughly 12 were trying). The inbound plane was struck by enough lightning to cause some damage, so all the passengers had to trudge from C-19ish down to C-1. Once everyone in the terminal booked on that flight boarded, they determined that there might be one seat available, called me to the podium, and told the crowd of potential standbys that there probably would not be any room on the flight, but that there might be one seat and if so "he (pointing to me) gets it". Most all the standbys left for the gate of the next ATL-FLL flight (grumbling), but one guy asked why I was at the head of the line - I gave a short "passengers who fly enough with AirTran to earn elite status get to standby before others" answer. Sure enough, there was one no-show & I got the seat (in Biz class) - the plane went out full.

21 March (Sunday): FLL-atl-[HPN for me, HOU for two traveling companions]

I used 4 credits again to upgrade my FLL-atl-HPN flights, but (at 5:30 in the morning before the flight, as soon as I could get a cell phone signal on my cruise ship) ATL-HOU was already full in Biz class, so I couldn't upgrade my fellow cruisers with credits. FLL-ATL went out full in Biz class, but part of that was a family of 5 who paid $ to upgrade that segment - I don't know if any Elites were upgraded; flight was totally full.

ATL-HPN had one seat left in Biz class; not sure about coach.