To iBM
Usually I only use 4 mix configurations. One for the full mixer, one for all groups, one for all fx and one for lead vocal and related tracks. I use the programmable buttons on my Mackie Control assigned to a configuration so I am one button away from getting where I need to be. On big projects, this speeds up mixing a lot. If there is a track combination that you would want see frequently, just program it in. And now that mixer configurations is fixed I am finding that I only use one mixer.
Dean