BK 12020 Problems

[giftacrylic]

Installed a new 12020 controller with a 8XL motor and the throttle seems very exponential instead of linear (it appears to have very little torque). Most of the throttle is useless when accelerating, only the last 1/4 max throttle really makes the truck move fast. When the truck is traveling at high speeds, I jab the throttle (about 1/2 throttle) and the truck has little or no response.

Things I have done:
1. Tried 3 radio systems
2. Cut wire and re-soldiered the system
3. Moved electronics so there will be no interference
4. Always reprogrammed the controller after every step
5. Tried several sized pinions

Could I have rec'd a bad controller?