Back in grad school our professor [Tom Holman](https://en.wikipedia.org/wiki/Tomlinson_Holman) did some amazing work in spatial sound, specifically for cinema. He chose to double the number of channels from 5.1 to 10.2 and the results were pretty amazing.
If my memory is working correctly, the channels chosen were Left, Left-Center, Center, Right-Center, Right, High-Left, High-Right, Left Surround, Right Surround, Back surround, and two low frequency channels. His research indicated that the human ear has better vertical localization towards the front (potentially having evolved to detect tree-dwelling predators, for example), and experiments with dummy head recording produced inadequate results for theatrical reproduction.
Sadly it doesn't seem to have caught on (yet), probably due to the expense of having to retrofit cinemas. Anyway, it was really cool to listen to. I imagine the use of ambisonic recording rigs will greatly benefit the 360° video playback experience. Don't know what the other use cases might be yet.