One thing I haven't seen people mention, with regards to rear traction, is whether they need it/have too much on or off power. When I first started driving the SC10 4X4 after driving my SCTE I noticed how much more off power steering it had. With my Losi I would brake hard and turn into a corner off power until I was part way through and then slowly feed the power back in. Attempting this driving style with the Associated had me almost looping out into the turn and then pushing hard when I got back on the gas. With how much more weight the SC10 has in the back versus my Losi I really had to adjust my driving style. By driving on power through all the turns I was able to get my lap times back down.
Anyway, just wanted people to think about the differences between on and off power steering when they're tuning their rides.