I find it kind of funny guys talking about giving up on there 05 pros after such a short time! Ill GRADLY purchase it off you, and I guarantee itll handle on carpet and dusty surfaces. its going to time, suspension adjustments, different tires and different inserts to find the sweet spot, but i guarantee its there! Get back to testing!
At a complete guess (havent even seen one in the flesh yet) sounds like the added weight of the servo and elecs to the back has given it a bad slide characteristic. Personally, id add more lead to the battery area, and a little forward of that, to get back to the original balance. Go to super grippy tires on the back and hard kit tires on front, and work your way forward. Follow the rule, get it to understeer, get rid of the tail sliding, and slowly creep up on front grip. If your fighting slides all day long, you will be there a long long time
