I have a 7D, and I LOVE my 3 custom settings on my dial.
This is how I use them:
C1 = landscape (low ISO, single shot, single point AF, aperture f/10, Av mode).
C2 = macro (Auto ISO, aperture f13, single shot, detailed single point AF, 3 FPS, aperture f/13, Av mode). I turn ISO to low if on a tripod and subject is still.
C3 = BIF / sports action (auto ISO, aperture f/5.6 or lower, continuous AF and fast FPS - depending on lens Tv mode of 1/1600)
Then in practice, I use the Av basically as a C4 part of my dial as a f/8, ISO 400 'general setting' - which I can decrease the Av to e.g f/2.8 for lower DOF. I nearly always set my camera 'back' to that when I turn it off.
Then at times, I use the Tv at another setting (usually around 1/200 or 1/30 for uses - eg panning). And I use often use M (manual) for flash settings.
I have really enjoyed using the 3 custom dial functions. I really want Canon to get rid of the Green Square (bleh) and Creative Auto (yuk!).
So then I hope the 7DmkII has 4 or 5 custom settings on the dial!!
The mirror lock up I have as a setting in my custom MENU (as well as other commonly used settings, eg Exposure Compensation, Format, Flash control). Mirror lock up for those special settings, eg night scenes, certain macros, etc.
I do also use the Q button time to time, but prefer to change settings with my eye to the OVF.