I have C2 set to One Shot and single point, C3 set to Servo and 61-pt, and the M.Fn button set to change modes – so it's one button press to go to Servo, two to go back (C1 is restricted).
Another excellent heads up, I have my own 1Dx Bodies set up in a similar fashion, I have a suspicion a lot of Canon users don't utilise this set up of being able to have 3 different set ups arranged at the flick of a switch (5DMK III) or press of a button (1Dx).
I must admit I do not use CF1, CF2, CF3 as much as I should - in fact I would really like Canon to allow us to name then or something. They are all set up as I want them, but I still rarely go to them.
As for the AF system, I find switching the AF system easier using far right button and the MFN to toggle between them. When I am at specific events I reduce what AF selections will be shown in advance to just those I know I will need.
The switch between AI Servo and One Shot is easy using the system as described by the OP, never liked the DOF button.
I spent a few days recently with a Phase One IQ250 and was pleasantly surprised to see they also have implemented the Canon C1 C2 C3 system as well, only thing unpleasant about the experience was the purchase Price, but 50MP & ISO to 6400, great stuff, 1.2 fps not so great, but those files are amazing.
Look on the bright side, at least it is not 1.1 fps!