These are pretty good out the box mate, very smooth to drive. All I've done to mine is adjust the camber to about 2-3 degrees, locked the rear diff, upgraded the servo, and fitted the radshapeRC chassis. Runs pretty well, going to order a 10.5t or lower brushless setup, front one way diff and a CS kit and I think that will be it. I think you can modify the chassis to run the motor up front, ill check a few websites as I can't remember who done this mod.
Had TT01s in the past but these sprints are a lot smoother and I much prefer them.
Enjoy it mate