In my opinion all mid priced "surround" mixers lack the same function, monitoring.
I would like to be able to hear 5.1 , solo out each channel in any configuration, fold into stereo, and fold into mono.
This can be alot to ask from a $5000 mixer, when a Martinsound "multimax" multi format monitor controller cost around $3500.
This is what I call 'easy to use'.