Well this has to be one of the hardest mixes ever. With 40 channels of audio, and heaps of spill going everywhere, it's really hard to control the sounds. If I could leave all the vocals out it would sound really good. But the vocal mics all have heaps of drums spilling into them, meaning that you lose all the clarity in the drums. When you turn up the vocal channels the reverb on the vocal also adds to the drums reverb, plus the indirect sound of the drums in the vocal mics makes for mushy drums. So lots of compromising has to be done as far as reverb levels and drum levels go. Also we have to remember that vibe is good. Try to get across the feeling of being at a live concert without it sounding too crappy.
The other thing to deal with mixing a live concert as I've mentioned in other posts is to remove all the mud from the sound. With loud PA systems and foldback on stage you get a lot of general low to low mid frequency wash that just muddies up the sound. So this needs to be removed, sometimes at the expense of the induvidual sounds. But that's part of the trick of making things mix well together. Soloing a particular instrument and making it sound good on it's own usually does not mean it will sound good mixed in with all the other instruments. So you need to treat each element in the context of what everything else is doing. I've gone through and edited the tom tracks and the percussion tracks cutting out sections where nothing is going on on those channels to reduce unwanted noise.
The other thing throwing me into turmoil is learning to use the automation on the SSL. It's great having this so you can record all of your fader moves. In such a large band with so much going on it's good to be able to shift the focus and also help in reducing the mud and spill, and the automation is very handy for this. But when you don't know the automation system very well you get yoursef in all sorts of trouble with faders jumping all over the place. It's a good way to scare people into thinking there is a ghost in the room, but not a good way to get a mix done when time is so limited anyway. In the long run it saves time because you can keep going back finessing the mix, so it's worth the pain learning how to do it.