I am the bass player and sound guy for a big band with a full rythmn section and a brass and sax section ranging from 6 to twelve members. We use the presonus 24 channel mixer. Set up is pretty quick and I disagree with those saying that it is cumbersome to set up.
The steps for set up are
1) Power up the mixer
2) Power up the laptop which has been programmed to run the software on startup and hook it up the the mixer - one cable.
3) Plug in the router. I don't even bother connecting the laptop to the router - they automatically connect wirelessly.
As the keyboard player, guitar player, singer and drummer (and myself turn up) their ipad/iphones automatically find the network and they just launch the app to control their mixes. One member from each section of the brass or sax section will control the monitor mix for that section. We don't need to do a monitor sound check any more (most are using in ears also) as each person can adjust their personal settings.
For front of house, I usually will start off with a saved scene and then use the ipad to go on the front of the stage and do a sound check with the band. The band usually starts off with an instrumental set and the singer will make any adjustments to the mix from off the stage during this time until it is dialled in.