Thanks Neuro - I use the camera custom settings (C1, C2, C3) while shooting volleyball to switch action and portrait type shot settings quickly but had not realized the potential you just revealed. I will definitely try this out - I especially like the M.Fn button to switch modes. The one thing I like less about the 1Dx than the 5DMKIII (in addition to the super loud shutter, OK 2 things...), is the lack of the dial to switch modes b/c the dial is faster.