The "posi-traction" on your Chevy is worn out Art... You better have that checked out!
The terms posi-trac, limited slip, trac-lock, etc, are all, basically, clutch type limited slip differentials. The different automakers have just given them their own flashy names so that when people are looking at the window sticker, at the dealership, they all say "Oooh, posi-traction rear end... NICE!!!". These types of differential have a 1:1 Torque Bias Ratio meaning that, if they are working correctly, half of the engines power is going to one wheel and the other half to the other wheel. The clutches are just there to provide some slippage while cornering because the outside tire needs to rotate faster. Once the clutches are worn out, the power is still being distributed to the wheels at the same TBR, but some of that power (To the ground) is potentially being wasted through excessive clutch slippage.
The Torsen diff does not use any clutches. Under normal driving, it acts exactly like an open differential and the drive wheels will operate completely independent of one another until it senses a difference in the torque of one of the wheels. It will then send (In the case of the T2R) up to 4 times the torque to the wheel with the most traction.
So let's say that you are going around a corner on a road course. The inside tire becomes very light and begins to spin. The Torsen will allow it to spin until it barely exceeds the speed of the outside tire. It will then begin transferring up to 4 times the amount of power to the outside wheel, whereas a clutch type differential will continue to apply a 50/50 ratio of power to the rear wheels under all conditions.
Again, if OP enjoys going around corners, he's going to be very happy with his Torsen differential.