I just did a MR this weekend from DCA-ATL-LAX, and on the ATL-LAX that left at 8:40 am on Sat, it was supposed to be the 777-200LR but they changed it to I think the 767-300, because on my selected flights, it did mention to 777-200LR both ways, but when I clicked the seat chart for the ATL-LAX leg, it came up with the 767-300. I did get the upgrade on the return trip with the 777-200LR.

I may have to do a run going between DTW and ATL or JFK and ATL to try out the ER seats if I can get the upgrade, and I'll be able to push myself over to Platinum level at the same time. Turns out my last MR leaves me short of that level by 1k miles.