My friend has one and won't go flying with it. He bought a 300F4 for his last trip, used, and then sold it afterwards. Not sure if that helps you any, but he chose not to fly with his.
Forget the case, it's a monster. I've carried it on the plane as a carry on with its lens cover on. I just had to camouflage it in a plastic shopping bag and it was fine. I then put it under the seat in front of me. I would not put it in the overhead bin.
I like the idea of a regular case, maybe even just my camera bag...
I carried the 500 to Kenya in a Lowepro Omnitrekker with the hood in my checked-in suitcase. There was enough space left for my 70-200, 24-70, 16-35 and 1D II. You might want to have a look at the omni trekker.
