Since I have been researching my possible next track car a 2010Civic Type R that has a Torsen LSD I came across this video and thought that it explained the workings well and was easily understood.
@ Waynne.
But on a serious note Torsens can direct more power/torque to the tyre with better grip while the clutch pack type only splits them 50/50 IIRC
Additional info The army Humvees have Torsen type diffs and the drivers are taught to apply some braking force to get them moving when there are 1 or more wheels off the ground.