Boom on 1 and 2 (MS),
lectro wireless 4 to 6.
Input 3 is an extra.
No problem at all to mix.
The trim knob is very useful to me as I often record iso, but mixing is also pretty easy with this small faders on channel 4-6. Even with gloves on it is much more easy to operate them than the grey gain knob.
The only down point is that you switch to pfl when adjusting a input configuration, for example invert channel 2. But I'm getting used to that.