I just tried a one-way diff on my TC3, and it made the rear very loose on the turns. I chose to use the one way because I wanted more steering power exiting the corners, thus I accomplished the exit speed I needed with the one way but all the adjustments couldn't stabilize my rear end.
I also realized that the Monster Horsepower motor didn't help my situation either because when I slow down near the turns, it tends to push the car forward, thus breaking my rear end.
I chose to go back to a diff since the turns are somewhat tight at my track but most of the fast guys are running one way.
I'm faster with the regular diff so I'm choosing to shelf the one way until I learn to drive better.