Harmy said:
They are all distinctly different mixes. The mono mix is very quite different from all the others.
I so want to a have a little featurette on the BD about all the different mixes, explaining how they're different and why they're all there but I don't have enough knowledge of the matter to do it by myself.
Such a featurette would be awesome! Nothing fance required, plain text will do :) Mavimao's summary was very good and informative.