All versions of the 9c have 5 point throttle curves. After re-reading my posts I'm not sure where that assumption came from.

Each flight mode is treated independently, you can have Normal, Idle1, Idle2, Idle3 and throtte hold. You can set up your dual rates and expo so that they are tied to the flight mode switch as well as gyro gain and even trims so that each idle up becomes its own flight condition much like the 9z

One example of a difference is the 9C will let you set up a mix that adds throttle as you add either elevator or aileron cyclic. It takes 2 P-mixes to achieve this and if you are already at high throttle it will still attempt to add the mix either stressing your throttle servo or popping the link off the throttle arm (a bad thing)

The super has a menu choice for Swash - Thr mix, you simply turn it on and set a percentage, no over driving the linkages or wasting two of your three available mixes.
The super also adds a gyro screen to the airplane software, and lets the glider guys have true flight conditions for trim and mixing which the 9c wont do and as I said the super has more onboard model memory.