Finally got some time to use and play with my S100. Here is how mine is set up today:
Ring Func. - metering mode (also like drive mode)
Control Ring - custom, M, TV, AV are defaults, P changed to zoom (don't really use P but I think I'll mimic AV mode for times I want a predefined focal length)
C mode - AV pref., AEB (2/3 steps), ISO 100, AWB, evaluative metering, flash off, default AV 5.6, drive single
My Menu
Servo AF
Spot AE Point
AF Frame Size
IS Settings
Safety Shift
Common
RAW only
AF frame size - normal
AF assist beam - on
Servo AF - off
Max ISO - 1600
Spot AE point - AF point
Safety shift - off
IS - shoot only, powered - on
GPS - on, Logger - off
Custom Display
1- shooting info
2 - shooting info, grid lines, histogram