I'm still playing with my set up. I find the control of the X-Mod isn't a smooth as the Mini-Z - there are 16 steps in the turning which does make it less precise. I found I was getting too much traction on the front end with the stock tires. Even with the stiffest springs I would traction roll or chatter and hop. I tried the harder slicks in the tire upgrade package and that made the car way more drivable - pushes a little more than I'd like but that we can play with.
There is a mod for the controlers to increase the range by 6 to 7 times so I'll investigate that and keep you posted (R20 mod - replaces a bias resistor for the output of the transmitter in case you want to look it up)