Roger, from what I gather there is not that much difference between regular 820 and aura unless you get into contrasty lighting with things like trees against skies when the halation kicks in a bit. I also heard that the Aura is a bit more demanding of subdued light when loading. Needless to say, I am we'll stocked at 50 rolls of each in 120 and 500 sheets of non-Aura in 4x5. I ran a roll of 120 last week and it is really a gorgeous film, the closest to HIE we will ever have I think.
That being said I *love* Rollei IR 400 just as much for it's stark look and tight grain, been shooting a lot of it this week for Fall colors. I hope that film sticks around awhile.