I am seeing some unexpected sorting when using original air date. If I have a series that has 2 episodes that air on the same day the episode that recorded earlier in the day would show above the episode that recorded later in the day. I don't think this is the expected behavior. Sorting by recording date, however has the expected behavior.
Edit: as a side note, this only effects series. The original air date recording is correct at the next level up.
I'm pulling the original air date from the wtv properties. For some reason it doesn't give me any time so there is no way to sort it within a given day properly. I'm not exactly sure how the standard recorded tv library does it.